Mitt Romney's due to address 1,200 members of the Detroit Economic Club at 12:15 Eastern, but he's due to do it in the Michigan Ford Field Stadium that seats 65,000 people. That's led to some shenanigans over how to arrange the logistics to make it look like he's not addressing an empty arena. However, to judge from the live-feed on CNN right now, they're having a pretty hard time of it. You can watch the set-up and the speech itself here.
Here's a pic: