I would also add that Peter had a 'fear factor' too. It was taking all his concentration to try and hold back the building energy burst that would destroy the city. If he tried to concentrate even briefly on using another power, especially one he has not used before, it might/would allow the explosion to happen straight away. So he stuck with trying to control the the power that was going to cause the explosion and left resolving the problem, i.e. killing him, to someone else.
Can I just say 'I told you so' at this point

Aside form Hiro's interesting little spin off adventure in the next season, I think I was right in suggesting previously that the first few episodes of next season will be taken up with tying up the loose ends of this finale. Things to be addressed include:
Has Nathan survived ?
Where has Peter landed after the explosion ?
Will the Cop and Nikkis husband survive their wounds ?
Will Peter and Nathan's Mum throw a major hissy fit when she finds out what happened to her plans for World domination ?

Has Sylar from the future dragged off present day Sylar's body or has someone else done it ?
Is Molly's super bogeyman just Sylar from the Future and will most of next season revolve around identifying this character ?
Which of this seasons characters will switch between being good guys and bad guys for no good reason other than it making a useful plot twist ?
Overall, this was one of the better series to have come out of the US in recent years so I'm looking forward to the second season...but I still think it could be a whole lot better if the plot twists made sense rather than just being included to make the series appear more involved than it really is.