[c-way-dude]

Frank Clair Stadium in Ottawa had a dome that covered most of the playing field during the winter. The dome was divided into three sections, and was used by a variety of groups. I believe the dome was privately run, and was quite successful.
As for the idea of a track, I hope that if the stadium were built around a track, there would be moveable seating to place on the track when the stadium was being used for football or soccer. A track might help lure an international event to the stadium in the future though.