I've been reading about this.
I reckon it is much more likely they have merged because GPU technology is far outpacing CPU tech. With current CPU technology reaching it's limits and with GPU's getting complete overhauls every 12-18 months, compared to 3-4 years with CPU's, it is a very smart move by AMD. They will now be able to incorporate much of the GPU tech into future designs, and have a proven team of engineers to do it efficiently.
Intel do not need to do this as obviously they have their own in-house graphics facilities.
Also, ATI gain about $400 million anually with it's chipsets for Intel. Presumably intel won't be licensing them for this too much longer, and that is a pretty big hole in the pocket for ATI?