Here's my theory: Hiro goes back in time as normal and meets the waitress as he intended. They become frineds, at least briefly, and he sees her get killed by Sylar, who would easily know how to find her if he had been able to track her down once already. Hiro is unable to prevent it, and the trauma galvanizes him into starting to take his powers and responsebilities seriously. He goes a long way to losing his romantic notions of being a comic book hero.
Meanwhile, it looks like Peter is able to track down Clare and is with her when Sylar attcks. I'm thinking that Hiro will miss this confrontation. So you have two "mimic" characters at odds with one another. If Sylar is able to kill Peter and take his powers, he will be able to mimic "specials" without eating their brains. This will give him LOTS of power since he would gain the benefit of extra powers without having to chance killing his victims. He would become more flexible in his terror. And if he does gain Peter's powers, then he could easily be the one who explodes in New York (losing control of what's-his-name's nuclear powers).
I doubt next week will be the climax of the season, but it's pretty obvious that it will be pivotal.
Oh, and Kid_Vid mentioned DL's SUV in the exploding picture. Did anyone notice Nikki/Jessica walking through the desert with a machine gun equipped with a grenade launcher? Well, looks like we know who blows up the SUV, although killing someone who can phase would still be pretty damn tough.
Gabriel
