Ok, just saw the last ep (above average, but not awesome I thought), so I can comment... :)
1/ Nathan flying Peter away seems silly to me. Came to mind episodes ago, and I'm surprising they took this (predictable) path. Peter can fly, and there could have been a heap of other possible solutions (going through matter guy, could have sunk him into the earth, or found a reactor... Hiro could have helped, etc..).
2/ C'mon - you would have thought that Hiro would have killed Sylar PROPERLY - beheading or something. Silly!
3/ Once a show has time travel introduced, ANYTHING is possible. Any character could come/be brought back at will.
4/ Definitely reminds me of Xmen - since the start. But its smart, that they have left it open to introduce almost any character or power at will. Looking forward to season 2!!
5/ What's with the eclipses? The 1st season started with one as well - do they signifiy the triggering of hidden powers?