I would imagine that some of that 60% have already moved (or are in the painful process of moving) to Vista. Other factors may be the economy (why blow capital dollars on upgrading if stuff still works today and the future is uncertain), or the switch to open alternatives such as Linux or Solaris.

As for PC gamers, we don't actually matter any more. Microsoft essentially killed off that market niche with the XBox and the overall push towards console gaming.