I am still on a wildlife photo shoot in Alaska. Canon may be ready to announce their megapixel camera some time late this year or early 2015. In a recent interview given to DC Watch concerning their latest wide angle lenses - EF 16-35mm f/4L IS and EF-S 10-18mm f/4.5-5.6 IS, Canon hinted their megapixel camera will be a good match for their latest high performance lenses.
Ever since the retirement of the EOS-1Ds Mk III, they are left without a professional grade, 'big' megapixel full frame camera and Nikon has been stealing their thunder with their 36MP D800 and D810 bodies ever since.
There are still discussion inside Canon as to which body style the new camera should take. My preference is for Canon to introduce it under the EOS-1 body first and then come out with a little brother version, say the EOS-3D or some other designation. Canon needs a professional, big megapixel camera to boast about and retake the crown from Nikon. They are experimenting on a few sensors, ranging from the high 30s all the way up to 70+MP.
Before Canon can release any big megapixel camera announcement, first they have to launch the EOS-7D Mk II camera. The EOS-1D X Mk II should get a replacement some time in 2015 as well.