My thoughts were actually the other way around:
Originally: Hmm, a first person platformer. This looks interesting, I'll try the demo.
After trying the demo: BLLARRRRRRGH!
No, it wasn't bad, I just felt it wasn't very polished. It made me feel a little disoriented (I don't get that with normal FPS), there was too much bloom, the graphics were nothing special, I heard the game was really short, and there was a non-existent story. I figured my money was better spent elsewhere (on LBP, Uncharted and Resistance 2, to be precise)
I'm not even thinking about it now, because the games (out right now) which I would buy above Mirror's Edge:
Fallout 3
Civilisation Revolution
Sonic Genesis Collection
Resident Evil 5 (and I don't even like it that much)
Portable Ops for PSP (I never buy PSP games)
etc.
So it's not that Mirror's Edge is bad, it's just not as good as a lot of stuff on the market right now.
(Former) Lead Moderator and (Eternal) VGC Detective 
