I'm attending both, though my cosplay lists aren't set in stone yet... Definitely bringing Lin Beifong to both (though don't know how long I'll stay in her at AnimeNEXT if it's very hot), and likely Ty Lee from AtLA... Molly Hayes from Runaways is going to NYCC along with Shadowcat from X-Men: Evolution.
The crowds at NYCC for 2012 were pretty bad on Saturday and Sunday, and I did miss the anime artist's alley, but the Masquerade for 2011 was a nightmare and that line was the single worst experience I have ever had at a con, ever
. Worse than the 2012 crowds where you could at least scooch around people to get to an open space, even if it did take a little finagling. AnimeNEXT was pretty bad last year, not gonna lie-- and it's my home con and the the first con I ever attended back in 2008 so it has a specia place in my heart. I was super disappointed and annoyed with... a lot. XD Hopefully this year will be better, though I know a lot of my friends who used to go every year will be ditching it this year because they just don't think it's fun anymore. :/