When version five was released the same crowd started wishing for features in version six the same day. You can make some of the people happy some of the time, but never make all of the people happy all the time.
The NAB annual show is at a date in the calendar that most manufacturers aim to put out a major release and feature release. Adobe tend to put out point releases but charge as if it were a major release. Unless they really have a major release of course.
Siggraph is the date for more computer generated characters/animation products. NAB for videography and broadcast telly/film.
Software is beautiful, you get it to last for about 12 months depending on when you buy it!
I just got out of Integrators on Ice here in the Windy City. I overheard one of the Sony guys telling someone about the cineform codec for use with their HDV camera. He said that the with version 5 it was the third party program/codec, but that in version 6 the codec would be part of Vegas. The guy asked about version 6 and the Sony rep said, in a couple of months... So I butted in and asked if we'd be hearing about that in Las Vegas and he said, "Yeah, at that OTHER trade show."