The Elementary stars and producers attended the TCA press tour today. They say many of the same things that they said at Comic Con, although now they say that Lucy Liu's Asian-Americanness is not going to be addressed on the show.
I'm not sure how I feel about that, being Asian-American myself. Sure, color-blind casting is fine, but I don't like not acknowledging a character's traits. No, Watson doesn't have to do karate moves, but I was hoping she would do some fighting or brandishing a gun when necessary. You want to avoid a racist stereotype certainly, but can still have fun with the character. I remember that in the original Star Trek episode "Naked Time," Sulu had a fantasy about being one of the three Musketeers and started fencing. But in later episodes, they disappointingly relegated Sulu's fights to Japanese katanas. Ideally I'd want Watson to kick ass, but not in a blatantly stereotypical way.
Alan Sepinwall has a much fuller interview with Rob Doherty.