I'm definitely going to both! My only confirmed dates are Saturday for AnimeNEXT and Sunday for NYCC, though, but I'm going to try to go all 3 for NYCC at least.
For AnimeNEXT, I'm definitely cosplaying an anime character- most likely either Morgiana from Magi or Miyuki from Lucky Star.
For NYCC on Sunday, I'll be with an Adventure Time group as Fionna!
If I go Friday I'll probably do Dean from Supernatural since I'll be going straight from school.
And for Saturday, I'm thinking of going as a Homestuck character- probably either Dog Tier Jade or Rainbow Drinker Kanaya, depending on if the latter is finished by then or not.