OMG someone started a Heroes thread and didn't tell me!? It's my new addiction! I've been looking for a replacement show to obcess over since Enterprise went off the air. I've tried Lost but it's just not the same!
Anyway Nathan is not dead!
I don't even think Peter blew up to be honest. If any of you read the comics and follow the Heroes 360 stuff on NBC's website, you'll see that Hana Gitleman (The girl that can access the internet from anywhere) blew up the other tracking system the company uses with the injected isotope, a satelight orbiting the earth. She got aboard it and ordered it to self destruct, killing herself in the process.
It'd be my opinion that that was the explosion we saw and that Peter got his powers under control at the last minute.
As for what powers new people will have, it's my opinion that Hiro's daddy Mister Sulu is imortal and is actualy that Japanese guy who owned the sword Hiro's got now. Forgetting his name atm.