You don't know what the hell you are talking about. Neogaf got insiders who deliver way more important information than IGN ever did. Maybe if you got out of your little mainstream gaming sites world and actually looked over the deep web and leak sites for information you would see not only IGN is late in the scale of months sometimes, but the information posted at gaf turns out to be correct.
And the $350-400 price being an evidence the 6670 rumors are right? Are youjoking or simply someone without the slightest hint on the pricing of manufacturing and hardware parts?