You are missing something major. The power of a GPU is not determined by the clock speed alone; in fact, most modern GPUs run at similar clocks speeds (within a factor of 2 or so). What differentiates them is the number of miniature processors each one has. The 8600M GT has 32 of the G84 variety, Sandy Bridge will have 12 "exectution units". Of course, the architecture is completely different so you can't compare them directly, but I don't think SB will quite reach the level of an 8600M GT.
Yes! And good riddance. It will take a long time and they'll never disappear completely, but they'll eventually be banished to a fairly small market segment. Once the integrated stuff really can match mid-range cards, GPUs become superfluous.
This is a historical curiosity. When AMD bought ATI, Fusion was one of the big selling points. In fact, it is explicitly mentioned in the
press release:
Keep in mind that in 2006, AMD was not the company you're probably thinking of now. Until about
the middle of that year, Intel was selling mostly NetBurst CPUs which were basically garbage: they ran at a high clock speed and drew a lot of power, but performed worse than AMD's contemporary offerings. Consequently, AMD's market share was larger than Intel's and it wanted to keep it this way by adding the GPU to their CPUs.
Unfortunately, they failed at this -- repeatedly. The press release says late 2008/early 2009, but it kept getting delayed and delayed and delayed. Notice that the first iteration will be released in 2011 and it's graphics will not be better than the contemporary integrated ones (or heck, even Intel's version of the same thing). So yes, AMD is essentially cannibalizing its own business, but it wasn't meant to be this way -- it's just that they're processors got less and less competitive while their graphics cards got better and better.
Problems? See this thread at archive.org.
