You have just made me realise a potential hazard for bitcoin.
The big GPU developers could collude with certain miners or traders to profit before others. For example: ATI could release a GPU which is faster if run with certain instructions and then release this code only to select miners. Another (much more likely) example: a new GPU design is created that hashes exponentially faster than the current generation. Traders know that this will cause a price shock, possibly sending bitcoins down in value. Traders dump their holdings and then buy back when the news goes public.
It's almost like the GPU developers end up being like a Federal Reserve which has to be impartial and incremental in their forecasts.
This is not something I had thought about before, but come to think of it, it is a pretty big issue. How can we keep the ATIs and NVidias honest if there is plenty of money to be made and there are no legal repurcussions?
I don't see how this would change anything with bitcoin, its how bitcoin was designed.
Bitcoins are distributed evenly, based on computational power.
So whoever has the best hash rate gets the most bitcoins.
In other words, whoever has more money to spend on hardware and electricity (or developing custom hardware), has the advantage over those who don't.
There is nothing stopping anyone from developing hardware to get a faster hash rate.
Just like GPU mining put the CPU miners out of business, the next generation of GPU's (or a custom ASIC) will put the current GPU miners out of business.
Its only a matter of time before it happens.
It wont cause bitcoins to go down in value, because the number of bitcoins being generated by the whole network is always the same.
If any new much faster hashing method comes around, the difficulty will increase to compensate.
It might cause bitcoins to go up in value, since they will be harder to generate, and miners will have to buy the new hardware in order to compete.