ROJH, yes Clinton has it in one (-ish).
I had the same issue only worse.Soon as I saw your pic I knew it immediately. I had late 2010MBP, all was fine til eventually updated to LION (sooooo much hate,now overweight from eating the rest of the bitten apple in depression...).
All went to the doghouse! Warranty expired 4 days before going to Genius,was going to CO$T big to replace RAM, which was fried,replacement also fried within 24hrs,went back & they replaced RAM again as well as now fried Logic Board.
That lasted just under a year,but with constant same issues.FRIED.Replaced RAM & LB again,lasted 3 months, replaced again & lasted less than 2 wks.
APPLE know of the world wide problem.Inherent manufacture point fails of GPU batches during production.I completely believe it's not 100% APPLE's fault (especially all store staff & Genius'), & I believe in the "design fault",but via experience I also know any version of older hardware is & was built to run properly with the OS it was designed & released for & with.As soon as you start going up in OS the heat goes up higher & adds to the 'cooking' of your wonderful toys.
For me,& it has been for too many others,as soon as we upgraded to Lion all went downhill rapidly.
Leopard & Snow Leopard are brilliant OS's,but if you want to keep safer, more secure & optimized, we are basically locked into the "Retail" version of Moore's Law.
I know this isn't 'the fix' for you, but as least you have a better idea on what's really going on.Good luck!