Why do you think Disney started with the fixed weeks option? I am very surprised since that is the very thing that has kept people far away from timeshare investments. Of course I do understand that your fixed week in a 1 bed lake view @ VGF is a lot different than the fixed week at Westgate Lakes down the street.
I stayed at VGF the other day, and I started talking to the DVC guide in the lobby. I was trying to get some dirt on the Poly, but he wouldn't confirm anything. He did tell me he thinks that VGF will be sold out by the end of the year. They are selling 33% are fixed weeks (although im unclear if he meant that to be they HAVE sold already) and said 2% are kept for cash sales, so already your chance to buy 'points' at VGF are limited.