But then it got popular outside of research labs too, so Nvidia has decided to milk the cow and restrict this feature only to their Quadro line-up, with ATI following suit. The result has been that they have pretty much killed the market - apart from those research labs nobody is going to buy a $3-4k Quadro card that has otherwise the same performance as a $300 GeForce only for the stereo support.

I think this sort of artificial crippling/restricting of usage to force industrial customers to use the more expensive hw they don't need otherwise will only lead to a proliferation of task-specific ASICs and Nvidia will hurt only itself with it. The reason why people use Nvidia GPUs for parallel computing is cost and ubiquitous availability, not because there aren't other options. This move will only accelerate their development - for which there were no reasons until now.