What's the catch?
Taken from the Apple Store for Education agreement page: Qualifying purchases per academic school year (July 1 - June 30): Power Mac, iMac, eMac, PowerBook, or iBook - One per year.
Buy now and you cannot buy again at the student rate for more than 11 months. It's not hard evidence, but it makes me think updates are not going to be massively delayed (although what is that anyway, I don't set Apple's release dates, Steve does) from the popular "6-month-cycle" expectations.
Maybe this pricing scheme is the middle road to keep the inventory moving and appease the group who would take a lower price over a better machine.
Regardless of when they are updated, if the 12" doesn't have a 1Ghz chip and a 2x Superdrive, then the wait will have been for nothing.
1st post -- thanks for a great site