Canon may be ready to announce the development of their megapixel camera some time late this year. 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 body ever since.
There are still discussion inside Canon as to which body style the new camera should take. My suspicion and preference is 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. There are a few sensors they are working on, ranging from the high 30 to low 40MP.
Before Canon can release any big megapixel camera announcement, first they have to first launch the EOS-70D and the EOS-7D Mk II cameras. The EOS-1D X should get a 'replacement' some time in 2015 and by then, Canon should have the megapixel EOS-1 camera on the market. Read my previous post on the megapixel project and the upcoming APS-C cameras release.