I'm pretty sure that CoP won't be open during MVMCP--at least it wasn't last year. As far as early December in general goes, it's not extremely likely, but it's possible. I remember last year someone posted that they got to ride it at the very end of November, but by the time I got to the MK (Dec. 4-7) it was closed again.
There has been *talk* about it being open to compensate for the lack of Alien Encounter this year. It would be nice, since without AE there are very few rides in Tomorrowland still open! I'm hoping, but not getting my hopes up too high.
Maybe if I cross my fingers with you-I'll be there at the same time. While the attraction itself isn't my favorite, I love the memories of when I first saw it at the NY World's Fair in 1963. Brings me back to my youth!