Seconded, I play a lot of singleplayer matches lately, and CAI is a pretty decent opponent. I think this would be great for our new players, instead of immeditaly joining the harsh world of multiplayer, they can first fiddle versus the CAI. It should also be easier to add bots, so that new players can easily create a singleplayer game, add bots to oposing team and add bots to own team. So that they can play a simple 3 vs 2 game or something, to learn the mechanics, while CAI also gives an example of how to counter certain units (Because CAI is pretty good at that).
I think that would be a great addition, especially for new players, because I bet most new players don't even know, that Single Player games are possible.