DL is looking expendable at this point.
My thoughts on characters thus far:
HRG - clearly running a military/govt operation involving these test subjects. The helix tatoo, the "bite" marks on the necks, the constant surveillance all point to a larger operation.
Nathan - This whole "Claire's dad" thing is fairly lame, but I guess we'll have to keep with it. I'm finding it odd that they're all romantically linked already. Some sort of superhuman sex commune? (ok, that's a little out there)
Claire -
Peter - I really thought the nuclear bit would be a result of coming in contact with Ted, and the "too many things to sort out" causing the explosion I don't have a handle on either. I think the parents story unfolding will play a HUGE part of this story, and I don't think that Nathan and Peter are actually brothers.
Isaac - finding it troubling that the edges of his paintings are misleading the other heroes. The T-Rex painting makes Hiro think he'll go back in time, and it leads him to go the museum. Since the painting is of him IN the museum, it COMPLETELY minimizes the "need" for the sword, but at the same time, makes him think he's DEPENDANT on the sword. This also caused problems as it relates to the Homecoming incident. I think his paintings will lead others astray here as well. While all of his paintings happen, they aren't all equally important (it appears).
Niki/Jessica - I think it's possible Jessica will die in the upcoming episode, but it could be Niki as well. As soon as Jessica is strong enough and/or tries to be strong enough, this resolves itself.
Micah - hard to say. I think he has "healing" power. I think he can fix things by touch, and/or manipulate (like he did with the ATM).
Haitian - playing the good guy right now, he mentioned that his gift was "from God" - I think he can find anyone of the main players when they are in trouble/in need (i.e. HRG, Claire, Parkman)
Parkman - the wife is going to come into play. We haven't seen anything here, but it seems that EVERY significant other has power. He needs to get HRG away from the Haitian. I have thought once or twice that the Haitian may be an alter ego of her Dad, his empowerment.
Birth mom - obviously, it was her power that started the apartment fire where Claire was thought to have been killed. If Nathan is indeed the father, I'm sure he just ran away, just like when his wife was in the car accident (although it's unclear if he WANTS to fly away, or if it's just something that happens to him).
Sylar - I haven't figured out hows he using powers of those he hasn't killed yet. Wondering if he is accelerating the development of the gene because of the way he's going about it, or if he's able to somehow "re-wire" himself with telekinesis.