"Halo Wars" is being done by Ensemble, not Bungie, though Bungie's said they've helped out with story background stuff. As to whether RTS games belong on consoles or not, I'm willing to see what the guys who made "Age of Empires" can do with a console UI before writing it off; after all, folks said the same thing about FPS games when Rare took a swing at it.
As to what Bungie's doing right now, all I know about is they're assisting Wingnut with that Halo-related gameish-thingy, working on the next crop of DLC maps for Halo 3 (almost finished), poking around on some s00pa-s3kr3t stuff they're not talking about, and (right at this moment, as visible on their web cameras) playing their Bungie Pentathelon.
-- Steve