Perfect Dark for the Xbox 360?! I presume you mean Perfect Dark Zero, of course. Apparently, it differs primarily in that the already un-beatable multiplayer was enhanced the only way possible: Xbox Live. However, this came at the cost of what appears to be a really lame single-player storyline. Of course, it's likely the multiplayer we were going to be getting it for, now were we? I wonder if my 1-year-old claims that it's MP would have Xbox fans saying "Forget Halo!" held true to some degree.
From what I remember of PD, technically, the multiplayer was incredibly flawed with some horrific slowdown. So I'm guessing the new version is more than a slight improvement.
