It is perfectly legal to begin selling units before they are ready for occupancy.
Right now
DVC is selling units in Kidani Village which will not open for nearly a year.
Before that they sold Jambo units starting 2/1/07 and they did not open until 7/2/07.
Before that it was different phases of SSR which began selling anywhere from 6-12 months before the buildings were complete.
As long as the state filings are complete and licenses issued, they can begin selling.