It makes sense that Hiro would be the one who could kill Sylar. Stop time, and chop him into little bits (now that he doesn't have Claire's healing power). We'll see if that happens in the finale.
Note the mention of "Molly Parker" in both this episode (one of the people Hiro brought to HRG) and in the previews for next episode (as a little girl). My theory: she is the "tracking system" that the company uses to track specials, sort of like a human GPS.
Gotta like that scar on Peter, it looks like someone slashed a sword across his face (wonder who). Why didn't it heal? Who knows. Also liked the little "grunt" and face Peter made when stopping time while rescuing Future Hiro and Ando. That was cute.
For a bit, I thought the woman helping HRG was Candace not Hana and I was confused by someone else I was sure of in the episode (more later). I should have guessed by the lack of sassitude.
Matt is bad! Bad, bad, bad. He apparently killed Hana and HRG and was going to kill Hiro. He got Claire killed. Even with the deception (more later) he was bad!
I pretty much knew it was Sylar! I'd figured that out from the promos and the plot. I was a little bummed when it was confirmed, as the story went from being about a complex no-win situation to Sylar being a crazy super villain. I still wonder how long he had been masquerading as Nathan and why *no one* had noticed. Didn't he act rather differently? Didn't Mohinder ever test (fake) Nathan? Didn't the Petrelli family wonder why Nathan didn't remember things he should have known? I guess Sylar grew into the job of becoming president.
So, Hiro brought DL, Candace and Molly Parker to HRG for hiding. Sylar had the powers of DL and Candace. Sounds like the hiding didn't work too well.
That last Sylar/Peter battle looked like it was going to be pretty awesome. You know those two are just going to rip the city apart in their quest to destroy the other. Still, Peter should win because he can stop time and rip Sylar apart so much he shouldn't be able to heal from it.
There were only a few people we didn't see or hear about in this episode: Linderman, Mama Petrelli, Claude, Ted, Meredity. It sounded like Jessica was "gone" - did Niki have any powers any more?
Overall, a very nice episode. Now we know what happens (Peter explodes) and what the result is. We'll see if the heroes can prevent the explosion. Well, of course they can.