Canon needs to come out with a video answer to the Sony FS-100, which has stolen a lot of business from Canon on the large sensor video market. Canon could have owned that new market on tails of the 5D2, but they slept on it and Sony snuck a lot of customers out from under them. especially now, since there's an electronic adaptor for the FS-100 that will take all Canon lenses and even the IS will work!
Ironically, one of the biggest complaints aired about the FS-100, is that many do not like the lunch box, traditional video camera body. DSLR's have such nicer ergonomics.
The 4K VDSLR needs to come out in April, to stop the Sony bleeding, especially now that Sony can use all of Canon's lenses.