So far Amazing Spider-Man seems to be voiced by Mike Vaughn from Web of Shadows (judging by his brief voice clip in the trailer), while Noir Spidey is voiced by Christopher Daniel Barnes from the Spider-Man animated series in the 90's. Possibilities for the other actors are Josh Keaton (Spectacular Spider-Man, Super Hero Squad), Rino Romano (Spider-Man, 2000 video game), Sean Marquette (Ultimate Spider-Man) or one of his Ultimate Alliance voices.
Anyway, I'm pretty excited to hear about this and I'll be watching updates on Gamespot. Also, despite the fact that I've always bought Spider-Man games on X-box, I'll probably be getting this on PS3.