I know you're new here (with 5 posts at the time of this posting) but you may want to alter the thread title to be a question mark, not an exclamation mark. I'd be shocked if the next 5-10 posts aren't moans and groans because they thought it was news on Space Marine and its multiplayer.
That said, from E3 09:
Daniel Acaba wrote:The four man squad has a lot of promise to it but Relic was mum on the issue of co-op or multiplayer at E3. Their only solid stance is that they are they are known for their good Warhammer games and good multiplayer elements. They're quite intent on making sure that this title does the universe justice. It stands to reason that there will be some sort of online multiplayer and a few comments hinted at the possibility that a competitive multiplayer component might pop itself up, allowing you to play as the Orkz.