Ok, so I've only seen the first episode, but I really enjoyed Elementary. Although I felt the mystery in that episode was a bit lacking that was partly because it was necessarily overshadowed by the set-up of the characters and their interactions, and it hinged on a classic bit of deductive reasoning. Holmes was recognisably Holmes and Watson was recognisably Watson, and both are completely in the public domain.
I'll make an admission: when I first heard that they'd cast Lucy Liu as Watson I made that kind of ugly snorting sound with my mouth that TV shows would have you believe fanboys and nerds make all the time and I said 'this will be terrible, it'll be a car crash, it'll be so funny.' But then I saw everyone else making those noises and I stopped and I thought to myself, 'that is a really ugly noise, and I get so angry when nerds get caricatured so, but the real terrible secret is that we do actually do that, maybe not all the time, but enough of the time.' And then I felt conflicted, and I decided that I would withhold my judgement until I'd seen more about it; until I'd actually seen an episode of the show at least.
But what's more, I decided I needed to examine why my knee-jerk reaction had been disdain. Was it because Liu was a woman, was Asian-American or had been in the high-camp Charley's Angels trilogy? I didn't want to be that person, the one who had any of those thoughts and let them go unchallenged. I also, I realised, was contradicting myself: I get really angry about the sexist and racist essentialism that tends to pervade my fandoms, and I'm a big believer in the legitimacy of re-interpretation, of the death of the author and all that jazz. There are plenty of reasons that the show could be bad, and a mishandled gender-swap could well be one of them, but this all needs unpacking further.
Reinterpretation is unavoidable. It happens all the time, especially in transfers between mediums, and here's the big, important, secret: it doesn't erase, or de-legitimise the original text. I know! Crazy, isn't it? Maybe the first time it's a wrench, and maybe it can be difficult if a character you love is completely changed or cast in an unflattering light in the version which gains the most traction, and you're left in a version of the story most people don't recognise. In fact, I know it's painful because it's happened to me. But the key fact is, you still have that original text to enjoy, to savour and to love. It's yours and it is never going to be taken from you. And I can bet as well that the way you relate to and imagine that character is different, even if only subtly so, to the way that the author thought about them when they created them. It's just how it goes; meaning changes within the interpreter.
On the whole I like re-interpretation, though. I think it is an important part of the artistic toolkit, without which we wouldn't have such seminal works as Romeo and Juliet, or such seminal train wrecks as Romeo Must Die (a glorious ultra-reinterpretation, as Jet Li's entire career to date, black gang culture and a vague idea of Shakespeare got re-interpreted into an floundering attempt to follow in the footsteps of the Jackie Chan classic Rumble in the Bronx, itself a re-interpretation of etc. etc.). My point is, although it is important for living authors to have some control over their IP, as it is how they make the money they need to, you know, go on living, if we lock it completely down we lose something vital in our cultural fabric for not enough gain.
I don't think I'm being controversial, either. A lot of fans and nerds would agree with me on those basic facts, if presented in the correct light. Without re-interpretation you lose most of the work of Alan Moore, you lose Doctor Who, you lose both super hero comics and opera in their current form, you lose Aliens and AD&D, The Wrath of Khan and, most importantly of all, My Little Pony: Friendship is Magic. Pertinently, for this discussion, you also lose Sherlock; the current darling of Holmes adaptations.
I think Sherlock needs to have a bit of unpicking actually, because an adaptation is exactly what it is. I like Sherlock, I really do, but it is not without its problems (a casually racist second episode, a lot of ham and a grating tendency to ignore motivation in its various villains), some of which would completely undermine a less stylish, less muscular show. What I'm basically saying is that it isn't perfect, and it certainly isn't a perfect Holmes - it's an interpretation of Holmes for the modern audience.
It works, and it does so in a way that the Holmes of Guy Ritchie for example doesn't, because it keeps certain aspects of the characters that are essential to them, and changes those which aren't; it's faithful to the essentials of the characters, not to the actual behaviour. Sexual politics is a good place to see this in action. To keep the dynamic between Holmes and Watson intact the two must be inseparable, and Watson must be willing to drop everything to go off with Holmes - and so women must be kept out of the equation. Conan Doyle's Holmes actively dismisses women as below his notice while his Watson feels no compunctions about leaving his wife to go on an adventure because that's just what men at the time did. Sherlock's Holmes doesn't understand women - he doesn't really understand people - but he doesn't think them incapable per se, while Watson is available to Holmes instead of being available to women, not as well as, because our culture puts a much higher burden of inseparableness on relationships than did Doyle's. There is nothing wrong with this change, it's just a basic bit of updating and it makes the dynamic between them - the really important thing - more accessible to the aforementioned modern audience.
I've not really heard people complain about this sort of updating, at least not consistently or to that level of detail. Yes, people do complain a lot about modernisation over period setting, but its usually at worst considered a necessary evil as long as the essentials are in place. And it's these essentials, and more importantly what we instinctively hold to be essentials, which I now want to examine further. Why is it that, without thinking about it consciously, a gender-swap is a worse crime than a time-swap or a location-swap? Why is it the I-could-cope-with-those-but-for-that of my reaction? Why hadn't I, and others, learnt my lesson with Battlestar Galactica?
We seem to be very good at mistaking the most superficial aspects of a character for the most essential. Sometimes we're right, but get our response wrong: Othello's blackness, or at least his otherness, is integral to his story but the fact that he shouldn't be straight-up white doesn't then justify all the blackface that goes on. But for a great many characters their skin colour is incidental to the core of the character, although it will naturally situate that specific instance of the character to a greater or lesser extent.
I think that it's much the same with gender - very few characters are essentially one gender or another, when you get right down to what makes them tick. I can think of only a few: maybe Miss Marple, who's M.O. is specifically feminine (and a specific form of femininity at that - being a village spinster), although she shares a lot of her technique with Columbo her (very plot-dependent) stories would break down quite quickly if transposed too far. Meanwhile captain Kirk has a certain hyper-masculinity to him that could also maybe be difficult to translate. I don't know though, even as I write this I can see ways you could play with both of those characters and make something new that nevertheless keeps something intact.
In opera you have what are called trouser roles, where a male character is played by a female singer. The thing is, depending on the singer, sometimes you just can't hide that it's a woman. In this way specific instances of the same work will have different meanings and gender politics - it's just how they are and is an integral consequence of the live, instanced nature of the artform. Similarly in most CRPGs which allow character generation allow a choice of gender, but that will only affect a very few points in the story - usually as few as possible to save on the amount of coding. Your essential decision points remain the same, however, regardless of gender - the essence of the character is unaffected although the way that you process the story that is told might well be affected. These examples of fluidity I think can be really instructive.
But, as I've said above, that superficial essentialism is hard to shake, and it is worse in fandoms like fantasy and sci-fi where there is already an edifice of racial-monoculture built into the metaphorical framework. But it is everywhere, really. So, I'm going to finish with one final exercise in self-examination for you to try, if you feel what I've worked through above is still a load of nonsense. If what is important about Holmes and Watson is that they are Straight, White men in (Victorian) London, why is the Guy Ritchie version so wonderfully bad? And why is Basil the Grreat Mouse Detective so very good?