You know, if a game isn't going to have top notch graphics, that's okay. It's not my preference, but I can enjoy a great game (especially one the caliber of the original Deus Ex), with graphics that are only average. However...
If I'm going to play a game game that only has average graphics, it had damned well better run great on my machine. I've tried the DXIW demo on my machine (XP2100+, 9800pro) at 800x600 with 4x anti-aliasing and I got about 15fps. That's unacceptable. With the same system, I ran Max Payne 2 at 1280x1024 and 4xAA and it was fluidly beautiful - never any slowdown, even with a lot of onscreen physics. There's no good reason at all why Max Payne 2, which was released a month ago, should both *look* better and *run* better than a big-budget game like DXIW.
Considering the poor performance and questionable 'simplifaction' of the game's interface and inventory management, I think cries of dumbing down for Deus Exbox might have some merit.