Canon are going to surprise us all and announce the 100mp 1.3 1D5
This I could go for, because it would have sufficient pixel density, and nearly the 1.6x crop... But, I really do hope that they do not merge the two lines. To me, it seems to be an advantage to specialize a little. Also, Nikon has both the D800 and the D400 up and coming. If Canon decides to drop the XD lineup into a single camera, this could cause many who are looking for a specific tool to look at the other side of the fence.
When fixing my truck, there are basicly two kids of wrenches: an adjustable wrench, and wrenches of many different sizes. I much prefer the exact wrench to the job than an all purpose wrench. In a camera, I want a camera optimized for wildlife/sports (what I primarily shoot). At some point, I will likely get a 5D. It will not be used for bird pictures or pitcher pictures. It would see its main use with landscape and portraits. I like to use 12mm wrenches on 12mm bolts, and 18mm wrenches on 18mm bolts. A camera which can do too much will do too little.