*dramatic music plays* Nyooooo! However a few managed to port over partially some of the unit models to Garry's Mod without textures. If he had rigged them and gave it the required textures it would've gotten some positive views. Linky ---> [link]
So would that mean people will port over many things from Starcraft II to Garry's Mod 13? I think that might cause a few discussions whether or not that is copyright since it is distributed elsewhere from someone else besides Blizzard. I am sure Gary Newman has enough problems already.
Once the game comes out, if people figure out how to get the art assets there isn't much Blizzard can do to control that. If somebody makes money off of swiped Blizzard art, then legal action is usually undertaken.