I'm a bit worried about the trailer's overreliance on Combat N' Gunz. That said, I did enjoy Mirror's Edge to a massive degree and I think a sequel, with the presumable budget and quality control expansions that it entails, could do wonders to the IP.
As for my expectations: I wish they'd make the maps a little bit more open this time around. Actually having multiple routes to the objective would be really nice, even if it meant cutting a little bit on the challenge and on the scripted scenes.
Also, I wish they'd keep the development cycle running a little bit longer after release. We all know EA won't let us have custom maps, so they could at least supply us with some quality challenge type maps (no floating blocks,ty) after we're done playing the campaign.
And for the love of god, if you guys are going to strap MP to it like you do to everything else, please, at least make it somewhat engaging. Here are a few ideas:
1) Competitive running: Place two or more players in a multiple-route map and let them race to the objective. To make this a little bit more enjoyable, let players interact. Setting up traps, making certain routes unavailable, tripping the oponent make for very interesting and refreshing gameplay elements.
2)Cooperative running: Set up a somewhat large map with several briefcases and clients. Have two or more players deliver as many briefcases as they can before the timer runs out. To make this interesting you may let players throw briefcases to each other, thus enabling them to overcome certain obstacles much faster (throwing a briefcase over a large gap or a moderately high wall).
3)Interception: Have one player set as a runner and one or more different players set as a foe (maybe a cop or a rival runner). Have the main runner deliver a package while the other tries to intercept it (probably wouldn't work too well with guns).
4)H.O.R.S.E: Set up a map with a single route consisting of very challenging series of obstacles. Have the players perform each series of jumps one after the other. Every time one of them fails an obstacle (maybe you can track this with triggers like "rough falls", "complete stops" or "time exceeded") they get a letter, first one to spell HORSE is the loser.
I firmly believe MP would greatly enhance this game, I just hope they do it right.