We've crossed the line some time ago on the "sold out" compared to actual butts in seats, and are rapidly approaching (for lack of a better example) JLA style crowds...where the announced crowd is significantly greater than actual attendance (witness most of the home basketball games as yet this season).
In my professional life, tickets are proffered for a variety of sporting events. This past football season, 4 tickets were offered in Section 1 (not THAT Section 1) for the Illinois game in the rain, and in the end zone for the Iowa game. Empty corporate owned seats, along with empty corporate owned parking spots, will make more frequent appearances, for all but the most desirable of games. This is not a blip, and won't stop, as long as the scheduling is weak for both football and mens basketball.
What would be interesting is to be the proverbial fly on the wall around the end January 2013, if the request for revised seating/PSD's into the end zone seats overwhelms the actual number of seats available...do the end zone seat areas then expand into the current blue zones? What if those carrying 4 seats in Maize, Blue, Valiant or Victors sections reduce to 2 or 3 seats instead?
Inelastic, meet elastic!