I think the NUKE is caused by not one person but by 2 or even 3. I think the fight between Peter and Sylar cause the NUKE and perhaps they're melting down when Hiro freezes everything and stabs Sylar..who blows up-leaving it up to the next season to find out what happened of it. Shall we break down the powers between the 3 'heroes?'
Sylar Peter Hiro
Freeze/cold power Everything Sylar has plus.. Time/place alter
Super Hearing Invisibility A cool sword
Radiation/heat Reading minds
Telechenetic ability Flight
Metal break down Invincibilty(unless brain attacked)
Artist future painter Time/place alter?
Librarian's memory -could Peter have the Haitan's Ability??
??
Advantage Peter, by a mile-which is why I never understand why he is always getting his ass handed to him--
Oh I forgot he doesn't have the Librarian ability so he can't remember all the things he can do and use them on Sylar 
? I guess it makes it entertainment(good TV) though to draw them up even in a fight.
We still don't know about the first couple folks Sylar killed and their talents...I guess the Ice ability is one we didn't know of until the last couple of episodes. Perhaps in the beginning ..was it 3rd episode? that they showed the 'board' where Mohinder pointed out how Sylar was killing others. Maybe he got his Ice from one of them..what else?
I'm glad the bastards in Linderman Corp(Incl. Linderman) got their asses kicked. I wonder though, about Linderman's heal ability......
I find it interesting that DL, Nikki and Micah never crossed paths with Peter... Imagine all the power he could have? Perhaps next year Peter will become the new villian?
DS
EDIT: I forgot Peter can take any ability from Sylar if Sylar uses it, so, NM on that comment.