"Sorry Peter, I always loved you."
Like many of you guys guessed, the hero who blows the other hero's head off is Claire and Peter respectively. Plus, Mohinder hooks up with Maya? Also, we get to see a power one of the Level 5 Villains had!
Heroes fans, you don't want to miss this promo video!
Watch it here!!
Also, a tiny spoiler: According to Brea Grant, Hiro and Speedster/Daphne powers cancel each other's out - when he stops time, she slows to regular speed. Source