A turnbased strategy game could work just fine on a console (like Civ Revolution was). Trying to do RTSs though would be a hassle. Not being able to do shortcuts with simple quick key presses like on a keyboard make it nearly impossible to make a good RTS.

I could see Civ 5 getting a console port. It's entirely possible for them to do that without any real issues besides it being a bit slower than mouse and keyboard, but, being a turnbased strategy game, the slower controls isn't a big deal at all.