HEROES Season Finale (ok, maybe spoilers in comments)

No spoilers... except to say that nothing that happens in the last episode precludes the future where the city blows up. All Sylar has to do is get Candice's power, like he said he did in the future. He can still nuke New York, become Nathan, and everything still turns out that way. Parkman just has to survive, and Ando has to die.

What is up with Sylar?? Why can't he be killed? He doesn't have regeneration powers like Claire... what is up with that?