I dont think Canon was planing on announcing new camera at ces however they need to have a backup plan. If Nikon pulls the trigger on the d800 AND d4, Canon might be forced to issue a press release of some sort. I mean they cant leave all the thunder to nikon for ces?
Canon has already announced the 1Dx, its Nikon who is playing catchup. The D800 in the rumor was a typo. Nikon is in trouble with the D700, they have not been able to sell D700's in Japan since November due to battery safety laws and have no camera to replace it.
About the D800; After years of R&D, when Nikon finally announces the D4, they would want it to get the full attention for a whole while, just like Canon did with the 1Dx. So I think there will be at least a few months time between the D4 and the D800. Sometime next summer or around Photokina sounds perfect for both the D800 and the 5DIII. Hopefully no more natural (or any other) disasters in the meantime...
About the D700 battery problem in Japan; Maybe a temporary solution would be bundling the body with the battery grip which accepts D3-type battery and sell for a bargain price?? This way they could also get rid off all the old D3 batteries (assuming D4 will have a new type) and 'win' some time with the release of D800.