It seems that the rumors about Nvidia's first DirectX 11 GPU, the GT300, leaving the engineering labs already in September are becoming more and more solidified.
These early demonstrations to partners are most likely targeted to divert at least some of the attention from ATI's release of their next generation graphic cards in September.
Apparently, driver development is one of the main reasons we haven't seen one of Nvidia's new babies in action already. Who knows? We might even get to see an earlier release to market than currently expected. This is highly speculative of course, though.