Peter--This pretty much showed that, without his powers, he at least tries to help though rationalization. Sure, he gets his ass beat, but still, at least his heart is in the right place.

Once he did discover what Jesse's power was (and the sonic scream effects looked really cool) you could really see the "Yeah, I played the son of Rocky Balboa in the movies once and I'm going kick some ass" look.
Future Peter--I guess the role for him this season (which, judging by next episode could be short lived) is the "mentor who sends the hero on his quest" cause frankly Peter's future self is way too powerful to last long. Although, we do get an answer to the question of how he transfered Present Peter's mind (and apparently body and soul) into Jesse.
Knox--Normally, in most comic books, the guy with the super strength is the dumbest of the lot, so it was refreshing to see a strong guy who actually has some intelligence. Yes, we get the whole "I was wrongfully imprisioned" defense (although what normal prision could have held this guy) but I'm already interested in this character. Plus he had the best line when he told Peter "Now I know you're lying. Nobody is THAT heroic."
HRG--We get to see more of Noah's calculating side this time around, which makes sense. After all, he's a normal guy who has to deal with super powered adversaries, including his new partner Sylar. The only time he lost his characteristic "nothing you do will intimidate me" attitude was when Sylar started slicing open Jesse, and pleaded for him that he didn't have to do it, which was a good touch. Also, letting the Haitain in on his plan to eventually kill Sylar when he finds a weakness underscores the level of trust these two have, which was also nice to see.
Claire--I like how they're starting to shape her character this time around, especially that her desire to be a "hero" stems from her need to punish people like Sylar because she herself was a victim. The whole scene in which Meredeth used her pyrokinesis to suffocating her own daughter inside the shipping container was pretty intense and probably one of the more messed up "parental lessons" seen on TV this season. Course, it didn't do a heck of a lot of good seeing how Claire has gone off to find the other level 5 prisioners by herself (which of course moves her further down the path of the "evil Clarie" we saw at the beginning of the series). EDIT: Although, if Claire was losing air because Meredeth was burning up the oxygen in the container, how was it that Meredeth was breathing normally? Talk about a plot hole.
Matt--Oh, great. So after walking in the desert with the African Bushman (who oddly enough can paint pictures that look exactly like Issac Mendez's (or should I say Tim Sale's) art, and finding out he would have had another wife and kid had Future Peter not interfered, but now Matt has the same ability to "paint the future" as well? Which means, I guess, "painting the future" was a form of telepathy? And you know what this means: more Tim Sale artwork for a third season in a row!
Tracy--So, for all those people who thought that she was Niki, guess you were way off, huh? Although, for a body that was caught in a fire, the undertakers must have done a bang up job on the make-up. And Micah's back (yay!) and apparently, along with his "talking to machines" ability, can somehow distinguish who people are and that they have powers, which I'm not sure how that ties in, really. Also, with the Dr. Zimmerman revelation, I guess hope to God that Heroes is NOT going the route that I think they're going--that Niki and Tracy are clones. God, that would suck!
Hiro, Ando, and Daphne--I found it more than mere coincidence that, when they were in the movie theatre, a Charlie Chaplin silent movie was playing (Or was it Buster Keaton? I couldn't tell). As though we couldn't figure out that these three are the comedy act of the series. Hiro is the "straight man," Ando is the "dopey sidekick," and Daphne is the "sarcastic moll." And we get another Batman and Robin reference (gee, you think Hiro and Daphne are going to be an item? /sarcam) and a further sign of Hiro and Ando's distrust, with Ando making the point that he's getting tired of being Hiro's "Robin." (although, technically, Ando was one of those guys who seemed a little envious of Hiro's abilities anyway, so it does make sense). Also, Hiro and Ando in Level 5? Hmm, I'm hoping we get a reunion between Hiro and Sylar next time. I would think he'd still be pretty ticked that the guy he called a "coward" had almost managed to kill him.
Sylar--So, it looks like he was adopted after all. And that the reason why he "feeds" off others with powers is because it's...part of his power? Are we supposed to believe that he'd be a normal, upstanding member of society if he didn't have the ability to see how things work? What about all that pressure from his adoptive mom to be special? Is that pretty much out the window now? Although, we still get moments of Sylar in bad ass moments, such as his washing up after his "snack," his pretending to be a FBI agent (which was quite funny) and, of course, his giving into the "hunger."