I don't have a problem with Warren Ellis and Salvador Larroca filling the pages of New Universal with celebrities. In fact I think the use of all those familiar faces is central to the whole comic.
We accept cutting, mashing and sampling in music and video so why not elsewhere? By moving actors and characters we know out of their original context aren't Ellis and Larocca just creating the comics equivalent of sampling?
New Universal is full of things and people we recognise in unfamiliar surroundings. It's our world but it isn't, part HBO show part superhero comic: the Sopranos and Lost spliced up with Die Hard and the Uncanny X-Men. China has a space station called Harmony orbiting the Earth, the Soviet Union still exists and the people we recognise as actors in our reality are nurses, cops and archaeologists in this alternate universe.
Ocasionally we see a face in New Universal that looks familiar. It takes a while to place it and when we do, we see that it's in a different place to the one we've come to expect. That give New Universal it's otherworldly yet familiar feel. It's a comic for our times.