Actually, much more is happening with CUDA beyond just gaming applications. Most folks are only familiar with the GeForce line of products, but check out the Tesla line of cards, for example:
http://www.nvidia.com/object/tesla-s...solutions.html
However, some of their Tesla-line cards cost thousands of dollars. Sometimes you look at one of their scientific-use cards and wonder why, if the paper specs are the same, they cost so much more than the consumer gaming card that uses mostly the same internals?
Part of that comes down to things I alluded to before, like backward compatibility with regard to what its used for. The GeForce line allows them to focus on gamers, and only be concerned with driver compatibility for games. With the Tesla line they can optimize for scientific uses and such, without worrying about goals for the gaming market.
For example, if you've ever looked at a big PC maker like Dell or HP, they typically have their website divided up into consumer and business models. If you look at the technical specs, a given consumer laptop that costs $1500 might be the equivalent of a similar business model laptop that costs $2500 or more. What's the difference? Why wouldn't a business just buy the cheaper consumer version?
Most of that comes down to availability of parts. If you're a large corporation ordering 500 of those laptops, you want to be damn sure that if you need to replace parts a couple of years down the road, that those parts are still available quickly (i.e. overnight shipment) from the manufacturer. Its critical when you have that many assets of the same type in the field. So, with the business-grade models you are guaranteed a certain level of part availability. Consumer models are meant to be sold onesy-twosey and there's no guarantee the consumer can get a replacement part quickly direct from manufacturer past the 1 year warranty, or if there is, it is supplemented with extra warranty cost and wait times.
It might seem we're drifting far from music related discussion here, but the concepts are the same with regard to CUDA. It's definitely a real technology that has valid uses, it's just that the scientific uses are niche enough that they need to pay a premium for same hardware, the primary difference being drivers that are optimized for their use instead of gaming. This would all be fine for audio, except that it would be a hard sell to a synth lover that they need to spend $3k-6k on a GPU to use it as an auxiliary synth or FX processor, the value starts to decline. The real value is in using the GPU that folks already have and I can see some hurdles to that.