The new villains seem interesting enough. I like to think that Samuel has good intentions (as far as that can be said about someone sending out an assassin) and that he just wants what's best for his people, whatever that is. I don't think he collects freaks for collection's sake, I think he wants to change something that happened, thats why he may need Hiro. Why he would need Sylar, Claire and Peter only remains uncertain of course.
I just hope it's not about destruction or being power hungry, that would make me yawn.

Sylar showing up in Matt's head was amusing. But I wished they wouldn't get rid of Nathan all that soon yet, when he turns into Sylar again. I am still pissed that Nathan got killed in three season finales. One should think that you are save if you survive two attempts on your life *sigh*

Hiro dying is a good idea. I mean even if he doesn't die, maybe he gets more serious or changes drastically otherwise, because his old self is getting boring. Or has been for a while already.

Claire's story was decent too. The suicide was quite a surprise. Of course the easy way would be to blame Gretchen, but maybe that's too obvious. Rumor has it they will fool around though, can't wait

A few minor things bugged me again, like so often in the last 2 seasons. Ray Park's power was probably speed and agility, not fighting abilities. Peter stealing said speed would not make him a decent knife fighter. But oh well.
We'll see where all this is going.