The big megapickle camera will not be branded as the 1DSx, for the exact same reason that, lo these many years ago, the compact Mac with a 68030 CPU was branded an SE/30 instead of, in keeping with the IIx and the IIcx, the SEx.
How about 1D Xs?
If only because Canon didn't learn from the naming confusion between 1Ds and 1D then yes.
Pity that when it comes to camera names Canon are incredibly so unimaginative.
Confusing only for the people who couldn't afford to buy it. I don't know anyone who mistakenly bought one for the other.
Actually, the only people I've seen complain about the name are those that have bought both the 1Ds series cameras.
So what do you suggest Canon name the new body?
(Big F______ Camera - High MegaPixel)