batman don't have a stellar, rated A record, but they're not all garbage. at worst, many of them get lost in a sea of mediocrity.
i really liked the animated series game on the SNES and the two on gamecube, so there's definite potential for them being good. the movie-based ones on the NES and SNES were pretty good, though they got a little tedious, but thats a general commentary on a ton of 8/16 bit games. i thought batman begins was pretty poor, as was batman forever and batman and robin. there was another comic-based one for the gamecube whose name i can't remember (dark tomorrow?) but that was pretty bad.
no idea what to expect from this one -- we dont really know what type of game it'll be, nor have we even seen a screen shot. im a big paul dini fan, so thats at least a good start.
i will say i find it pretty amazing that there's no "the dark knight" game yet. this might be the first blockbuster to not have a subsequent game in years.