Most people who would care to upgrade probably already have something at least that good. If they didn't, I doubt they'd be willing to pay $250 for a mid-range product from half a decade ago. I think a product like this only appeals to the same sort of people who hear about a shortage of toilet paper and rush to the store to buy a cartload for themselves even though they already have plenty and won't be able to use the additional rolls for anything.Well, I was talking about the 4GB versions which still go for $200-250. (That goes up every time I look though! The point being if you give them enough vram for mining their price balloons drastically. As mentioned the point is to release something that doesn't really work for mining to try and keep the gaming market from dying, even if it has to live on 1080p life support.
The PC gaming market isn't dying. It won't be too terribly long (I'd say 3 years at most given that top-end Cezanne is on par with 460/560 in terms of raw GFLOPs) before APUs can deliver the same kind of performance that a 480/580 is capable of and the PC gaming market is larger than ever before when viewed from the perspective of people who can reasonably game at 1080p.