I liked Mirrors Edge, but the combat ruined it for me - no good being a bad ass parkour chick when your surrounded by dudes with guns, the game just didn't let you deal with situations in the way that made sense to the gameplay. I'd rather have a more casual game like that, less being chased and dealing with dudes with guns, and more about finding the fastest route across buildings, maybe a race. I mean, the courier thing was there from the start, then gradually the plot turns away from that. What generated the buzz with Mirrors Edge, was that demo, people played the shit out of that, trying to get a perfect run... the game descends from that point IMO, your not doing anything more interesting than in that demo.
If it was up to me, I'd make a multiplayer version, make it more like a race (get to the case, get the case to a drop point, while opponents try and stop you. We don't get too many games that are multiplayer, where the primary focus isn't just killing. Even Kane and Lynch, with it's bank robbery multiplayer games was good fun. Maybe I'm just sick of constant FPS games, but dammit I'd play Mirrors Edge to death if I could do away with the constant enemy funneling.