We have a winner for our fanboy of the day award!
More seriously, it just wouldn't be a wise investment on either Take-Two or Sony's part. The controls would be awkward at best, and the market for console peripherals (keyboard and mouse) has always been a niche. Assuming everyone who wants a console Civ4 would purchase a keyboard and mouse would be like assuming everyone who purchasing a driving game will buy a steering wheel - not going to happen. Furthermore, how many people are really going to buy a game that's been out for over 18 months now on the PC? Anyone who wanted to play Civ4 has almost certainly already gotten it. I don't see the sales being high enough to cover development costs.
And for fun:
Your beloved PS3 doesn't seem to be doing too hot there, chief.

Now I don't care one iota who "wins" the console wars, but fanboyism is a plague befalling the Internet - and tweaking the noses of fanboys is just too much fun to pass up.