I think all this conspiracy hypothesizing is hilarious. Think people! If the R600 was all that, why the stupid NDA?? It made zero sense. It's not like they could be afraid of cannibalizing their own sales when they currently have nothing in the $300+ market atm to cannibalize anyway.
The writing was on the wall about this for months. The rest was all fanboi hype. The mid/low end products are 10x more important anyway.