I think this is inevitable. Especially with the Nikon D800 rumors coming out with 36 megapixels and no AF improvements either. It just sounds like both brands are trying to make up for the fact that, given this economy, there is no market for an $8K high-res camera anymore. They've realized that the best market for high-res is in the $3-4K range. The 1Ds mk3 and D3X sold well, but not as well as the 1DX and D3s will sell / have sold. And not nearly as much as a 5D mk3 / D800 would sell.
HOWEVER, don't forget that Nikon still has a D4 coming, and Canon still has the opportunity to make an affordable 1DX.
It's pretty understandable that Canon will NOT be able to make an "affordable version of the 1DX" right at the same time as the 1DX hits shelves. Like the D3 and 1Ds mk3, we'll have to wait about a year for the affordable version.
So, after the 1DX this march, I'm predicting a 5D mk3 shortly afterwards, as well as a Nikon D4, (in time for the summer olympics, right?) and THEN, within 12 months of next march, we'll see the lower-resolution, "affordable" versions of the 1DX / D4.
The only question is, will these cameras be super-cheap, with 60D / D7000 body parts, or will they be high-end, like the "3D" or 6D (basically, a 5DX) rumors have been saying? I dunno, but I'm hoping for the latter!
By the way, I posted more thoughts about this particular rumor on http://slrlounge.com
...as well as my 2012 Canon predictions in general. (24-70 mk2, etc.)