Yeah, I don't care about Claire any more in fairness I didn't really care for the character in the first place. Also they seem to have killed off the whole Noah's a good guy looking out for his family vibe that built up in Season 1, he seems to gone back a couple of steps in character development, here's an idea, Haitan blocks powers so put him and Sylar in a room and shoot him in the head, problem gone.
Yeah Hiro and Adam continue to make this show awesome, my favourite part last season was the Hiro's in the past bit. The whole Peter now has Sylars power now could really backfire on them, and they need to depower both Sylar and Peter. Uber powerful good guys aren't that interesting for long, see Wolverine, Cable, Superman.
And Nathan's power is artifical, interesting to see who elses is as well.
I think there is still some hangover for the crap that was the second season. You can only blame the writers strike for so long. They need to get back to what made Season 1 so great. I watched the whole of S1 again and watching all together, its just a slow burn till it explodes at the end and the pay off was great.