I don't think they knew it would help. Did Nathan know that Peter had learned regeneration beforehand? And their mother said she'd known about their powers for a long time, but that doesn't mean she knows specifically what powers Peter'd picked up.
And regarding the whole Sylar thing, Issac mentioned to Sylar that he'd show the others how to kill him. Before Sylar arrived, he handed off his final comic to that asian guy. Is that the same one that Hiro picked up in the future? If so, they just need to look at that to know how to kill Sylar. If not then they need to get their hands on the most current issue. Though I don't imagine that will stop the explosion. Honestly though, I'll be sad when Sylar is dead. He's my favorite character.
And what's with everyone assuming that Sylar's "eating" the other people's brains. There hasn't been anything to suggest that. In my mind, the power works in the same way that he was able to fix watches. He "opens them up", looks at them and tinkers around a bit, and the watch is fixed. He doesn't eat the insides of a watch. Why would you assume he's eating the brains. Also, at the end of this episode when he's painting the painting the picture of Nathan in office, his hands are all bloody, but there's no blood around his mouth. If he'd been eating brains, you'd think there would be. Rather the blood on his hands suggests that he was "tinkering" with Issac's braing to "see what made him tick." Then he somehow is able to make those changes to his own brain/dna/whatever. I refuse to believe that he's eating brains. That's just silly.
And I'm thinking the voice thing is just something he does by manipulating the air coming from his mouth simply to add dramatic effect. The whole point of Eden blowing her brains out was to keep him from getting her power, so why give it to him anyway? Plus like other had said, he's used it before when not giving a command and even before he met Eden.
If you choose not to decide, you still have made a choice.
Lassev: I guess there was something captivating in savagery, because I liked it.
