Hiro SPECIFICALLY says, "This is what you have been waiting for." Well, what has Peter been waiting for...
Peter (10 times or so in the show): "Sometimes, do you think you are meant for something greater."
Well, this leads me to believe, Hiro tells him to save the chearleader. By helping her, Peter becomes part of something bigger, which is something he has been waiting for, which is in effect, saving the world.
Now some Hiro/Explosion Series
1. There is no reason to believe so far, that Issac's paintings never happen. They always happen at this point (7 years later (umbrella rain picture), or days later. But the explosion happened once already, does that mean the painting occured and this time it won't.
2. So this can tell us nothing the Heroes can EVER do will stop the destruction of NYC.
3. But, Hiro comes from the future (OBVIOUSLY after the nuclear explosion) and talks to Peter. So obviously they failed, never met, whatever. What if this is NOT the first time he is coming back, what if they failed before. Why now? If fate is true, coming back in time won't change the future.
4. If the future can change and we believe in free will, then they can stop the bomb the second time.
5. What is it to say that the first time they failed, Hiro didn't contact Peter in that timeline too?
Anyways time travel is confusing, no one can understand it until the creators explain it in the way they view time travel. It's all subjective until time travel is a tested law of physics.
