Squee! Should be fun.
As for Shawn and Derek's repeat dance:
I imagine Derek will add just a bit more of quickstep so the judges can't say there was the same or less dance content, but he'll keep the hijinks up because his strategy all season long has been to appeal to the viewers, not the judges. Their "quickstep" had precious little quickstep IN it, but it's one of the most popular dances ever done on DWTS. For the most part, viewers crown the champion and in this case, the judges don't disagree enough to pull their sway, ala Jennifer Gray.