I'm also suffering with this issue (the GPU) on my 17" MacBook Pro - early 2011 (MacBookPro8,3) and incredibly I had initially first experienced this issue from within the first year I had my MacBook Pro, approx when the unit was only 5 months old when it first happened. I initially thought it was a software glitch/issue because it was very seldom and intermittent and after experiencing it for a few months, it then eventually went away.
However several months later the same problem started happening again with the same characteristics as before being intermittent (random) and only occasional. By this time the initial year had just passed and I thought that the problem would eventually disappear as it had done before. Regrettably the problem did not entirely go away; instead it would have phases where it would happen intermittently and then disappear over periods of time and this served to confuse me more making me think it was possibly software, drivers or even conflicting third party software (**** even viruses). System reinstalls were performed many times and even upgrading to newer versions of OS X's in the hope that it would resolve the issue. Even hardware checking programs like Tech Tool Pro had apparently reported the hardware as ok. However the problem still exists and has started to happen with greater frequency.
After coming across this post I now realize and see that all affected owners here are in a hopeless situation. A genuine design and manufacturing flaw is beyond our scope and ability to fix as mere humble Apple consumer's & owners whom invested heavily in what was portrayed, sold and believed to be a 'premium' top of the range flagship mobile Mac computer. It's now quite clear that this problem is a genuine design-manufacture defect and one where the ONLY solution and recourse for Apple being to do the responsible thing for setting in motion the procedure of issuing a 'recall' for all affected owners at the very least or at the very most recalling all MacBookPro8,3units and offer a genuine final solution to the owners for either:-
1. Fully resolving the design-manufacture flaw with a genuine hardware 'repair fix' consisting of any necessary re-designed components that have been tested, shown and proven to fix the issue.
2. Exchanging the faulty units/models possessing the design flaw, by giving the owner the choice of either a different replacement Apple Mac or Apple products amounting to the same value (and allowing affected owners the flexibility to pay the difference if the value of the replacement chosen Mac/product exceeds the value in anyway as there is no identical replacement because models have changed - this would be fair all round.
3. Offer a refund.
Although it may be thought that owners would have got some usage time out of their heavily invested premium priced machine, however in reality affected owners including myself have actually suffered much stress, anxiety, inconvenience, headache and loss of confidence.
Apple do not need to ignore this and do not need to feel for one minute that this would hurt, damage or dent their reputation for prestige products, nor does Apple need to feel that if by admitting there is a design flaw by issuing a recall that it may portray some of their equipment as inferior; in fact it's quite the opposite - if Apple do the right thing by recalling all affected design-flaw units, then they will re-instill and inspire full confidence once more back into all affected owners and also serve to impress and project greater confidence into newer customers knowing and seeing that they would be in good hands if considering and buying an Apple product.
It's one thing buying a purported to be prestigious, top of the range, highest quality (premium priced) Apple flagship product... BUT a completely different thing if that prestigious product wont even last a decent run of time becoming an extremely expensive paper-weight in less than a few years.