After retailers had started sending out messages to customers who had pre-ordered This is Vegas that the title was cancelled, the internet assumed the worse. And while the worse is sometimes true it turns out Warner Bros had not decided to cancel their recently purchased property (yet anyway).
G4TV got the following quote from a representative:
"This is Vegas has not been cancelled. The game is currently in production."
Given the change of publisher it may be a while until the game is shown again, but at least we now know it is still in development.