Well, this guy never sits still, does he?? According to the interview he did with Extra’s Teri Seymore on Saturday before the BAFTA’s Brits to Watch Party, he is doing some choreography for a “Cameron Diaz, Matthew Morrison movie” in August, which he says will be completed before “the show” comes back. I assume he’s talking about DWTS. The movie he’s referring to is, I believe, the anticipated “What to Expect When You’re Expecting“, also starring Jennifer Lopez and Chris Rock. Now, since Derek doesn’t come right out and SAY that’s the movie, I’m guessing. But I think it’s a pretty good guess.
ETA: According to Mark, Derek will be back on Season 13, but he’s not sure about his own future: