Don't think AMD would go under completely. At least I'd hope someone would buy them out. Maybe split them up some. But completely bankrupt leaving no competition? Nah.
None of this is a surprise, though. Their computers suck ass. Still a lot of decent hardware/components, but that doesn't pay the bills nor win public opinion usually. I remember at my last job one quarter there was a massive switch from Intel to the 'new' AMD A-# processors, and holy shit it was a tough sell and you couldn't even lie to customers as even the most ignorant knew they just weren't as good as anything Intel in a laptop.