I think I'm going to be picking up the Eidos collection on Steam, if it's on sale for the holidays for $50-$75 again. So getting Batman now would be a bit of a waste.
A cool sale I just saw in the comments at RPS is Puppy Games' back catalog (Ultratron, Titan Attacks, and Droid Assault) for $4.97. Just the sort of deal I was waiting for, and puppy games have a pretty good system, after you buy the pack all you need to do is download a game's demo and type in your email address and it's automatically registered. Since the demo's always going to be available on a mirror somewhere you don't have to worry about the store's redownload policy.