I'm pleased that the whole 5D range hasn't moved stupidly up the Canon model range. The idea of using the 5D body for a range of solutions echo's the previous 1D strategy, but at a much lower price point,

5DS - High MP monster
5DS R - High MP without Low Pass filter
5D Mk IV - Evolutionary improvements on the Mk III

Could we see something similar in the 6D range as a lower cost alternative ?