Well that was a pretty decent end to what was pretty much a not so bad but not all that great "volume." I always had a feeling that since the start of the show, they were going to have the "good brother vs. evil brother" angle going with Peter and Nathan somewhere down the road, and it looks like that's what we now have, although Nathan saying that he now wouldn't save Peter if he was in the position to save him as Peter was? That seemed a bit much, even if he was mad at Peter destroying the formula and ruining their father's dream. At least Peter has his abilities back and most likely has to acquire new powers (technically, he should have Flight from Nathan, Pyrokinesis from Flint, and Super Strength from Mohindir right now--unless he's back to having to physically be around a person in order for him to use those abilities again.)
I did like Sylar playing his little mind game with Claire, HRG, Meredith, and Angela with his whole "you're just as much a monster like I am" relativism argument. Not to mention how, even though he realizes he was lied to by Angela, still wanted love and acceptance from her as though she was his real mother. And while he did make work of the level 5 villians--especially that Puppet Master guy--I'm surprised he didn't try to take their powers afterwards. Although an interesting twist was the confirmation that while Arthur and Angela may not have been his real parents, Angela didn't lie to him that about him being adopted by the Grays. Obviously, next volume is going to be Sylar's quest to find his real mommy and daddy while on the run. Oh, and I don't think for a second that either Meredith or Flint are dead, considering they are both fire proof, after all. Not to mention it would be a real waste if they spent all time with their backstory in that flashback episode and not explore their brother/sister relationship. (Then again, this is Heroes).
One moment that I do have a bit of a problem with his Ando gaining "ability boosting" powers. Part of the appeal of the character in the first place was that he's supposed to be the normal guy, the straight man the audience relates to. Now, he's no longer the identification character per see. I do get that the creators of the show wanted to limit Hiro's teleportation/space-time manipulation abilities, however, and my guess is that the way this will work in later episodes is that in order for Hiro to access those powers, Ando has to "supercharge" him and it will only be for a limited time. This not only limits time travelling, since it would be "too risky" for Hiro to use as he might get stuck again, but it gives a reason to keep Hiro and Ando as the "dynamic duo" of the series.
Another duo I guess will be Tracy and MohinDUH!, and they'll probably play up the idea that Mohindir had an attraction for Nikki and since Tracy is identical to her, well, there you go. It's also clear that they've paired these two up to look further into Tracy's past and her origins. Also, am I wrong to assume that because MohinDUH! was bathed with the formula, he still has super strength without the brundlefly effects?
Well, best moment was Hiro decking Tracy with one punch after being called Pikachu. Coolest moment was seeing Michael Dorn aka Worf as the President. Cop-out but in a very "holy S*** I didn't see that one coming" moment was when Knox snaps the neck of "Captain America" before we got a chance to see him do much of anything. Bigger cop-out and "Gee, guess this proved he was a real waste of time" moment was Tracy freezing Knox to death.