From the above picture (Table 5.4) we can clearly see that $0-100 Graphics Cards (both ATI & NV) represents 60.18% of the total Desktop Discrete Graphics Cards market. 
(ATI 3584 + NV5714 = 9298   out of 15450 Total)
		
		
	 
	
	
		
		
			I foresee the >$150+ GPU market to become > 80% of what's left of the discrete GPU space on the desktop.
		
		
	 
That seems likely, with consol ports being playble with less and less expensive hardware. Id assume once 28nm is out, unless new consols are too, we ll see the sub 150$ market take more than 80% of the total sales.
I mean its over 60% now, and its bound to grow as they keep makeing stronger hardware but titles stay the same, consol ports.
*IF* the integrated GPU (in processors) ever become strong enough to match the 100$ discrete ones, that would push Nvidia out of 60% of GPU market. Now that probably wont happend anytime soon, and might not happend at all, but it could. Currently Llano is roughly able to match the 50$ cards.
Nvidias future profits are gonna lose more and more, to integrated GPUs, which is a problem because more and more consumers are useing midrange or lower cards.
With AMD doing a new arch for more compute power in their gpus nearly identical to nvidias approch, thats bound to cost nvidia some sales in the server market too. Nvidias low-end and high-end(server) are gonna shrink.
Which is why Nvidia are putting so much effort into their Tegra lines, they ll need that to survive, in mobile phones.