After years of doing its PR ratings, AMD is planning to get rid of it. Just as the Opteron names make next to no sense at all and Intel's new model names that doesn't reflect real world performance, AMD wants to do follow suite and bring out its own model numbers.
The only logic with the Opteron model names today is that 1xx means single CPU support while 8xx means eight CPU support and that's about it.
The K10 generation should be the first to be free from the PR rating. All this comes from the horses mouth.