@Moria:
It showed him using Ice back in the "future" episode where Hiro goes into Future with Ando. I don't know where he got ice though, pretty wierd. However, it seems like some of the final battles will be Sylar Vs. Peter. They are both insanely powerful, with the powers of other Hero's. I'm looking forward to the season finale. Isaac finally died, he wasn't relaly much to the story.
If you think back to the second episode, the one where Matt Parkman was at the crime scene of one of Sylar's murders, the murdered family (minus Molly, the girl from this latest episode) was frozen to death by Ice powers that Sylar had. If you think about it, Sylar has Ice powers, Peter met Sylar, so he technically has access to all those powers that Sylar had at each time Peter's met him.
Now we know what that Molly is the new tracking system, and quite an unbeatable one at that minus the genetic-destabilization making her unable to locate people.