I was under the impression the "the Collective" was a completely new guy. I'm pretty sure I read somewhere that he's just some unlucky man(somehow in space) or alien that absorbed all of the powers of all of the mutants that lost them, but has most of them under control(thus rendering "what about unwanted mutations" arguments futile.). Hence "the Collective".
In fact, I'm sure of this. Joey Q said "All of those powers had to go somewhere." This would also explain the powers other than fire(which is the idiot's observation of his power) on the #17 page that showed him battling Alpha Flight. One of the members looks like she's being attacked by bugs. Plus, look how well that ties into why House of M is being talked about in Avengers.
So this guy, this "Collective", is in effect this huge threat because he is every depowered mutant.