Theres no way a 5DMK2 replacement will be announced before Xmas imho
If the 1DX availability is so far in the future from actual announcement, i cant imagine the 5DMK2 replacement will be available before the 1DX.
Therefore why announce the 5DMK2 replacement before Xmas and potentially kill a hell of a lot of prosumer Xmas sales. People like to buy themselves a present as Xmas, some sort of justification, and the 5Dmk2 price point is exactly that.
The 1DX announcement didnt matter before Xmas as its not the sort of camera that sells as Xmas presents, so getting the word out there that Canon have some amazing new tech (in thier opnion) will help save face and customers.
I think Canon are struggling more than they let on imho.