tannat, could you PLEASE change your terminology? A product with positive gross margins but negative operating margins is NOT 'selling at a loss' - every unit is making a profit. It simply did not amortise the R&D/marketing investment over its lifetime. Until everyone insists on using more precise wording, this discussion will go nowhere.
The burden of proof is clearly upon anyone who claims NV or AMD are selling some products with negative gross margins, but arguably it's also upon anyone who thinks every single one of them has paid back its investment. Someone who claims a specific product (e.g. GTX460) did not, however, also has the burden of proof. Obviously, you can always say something is at least possible, but you're not allowed to make ten posts repeating that either *cough*
There, now that we've set the rules of this silly little game, could we stop playing it?