It's a pity Nathan isn't just plain screwing Peter. [/twincest joke]

I really hope they don't kill Matt off this quickly, that would piss me off. And with such a powerful ability, it'd be ridiculous for the writers to waste it.

Perhaps with the absence of Sylar, they're just excluding him for now to make you wonder what he's up to. As for Mohinder... give him a break, he's torn between idolizing his father and hating him for what he did.