We used a room-only general public code for our Easter '05 trip. There were lots of codes when we booked: AAA, AP, room-only general public and package general public codes. Historically, the smallest savings is AAA and the largest savings is AP.
We had been thinking about buying an AP even though we had no other trips planned, just for the AP room-rate.
Well, at least for our time period, the AP and public codes were almost the same savings -- something like $5/day difference -- so we passed on the AP and bought park tickets from a discount broker (Hotwire, which I read now doesn't sell them anymore??). Better prices for us to go this way.
2006 may be more popular than 2005 thanks to Disney's promoting 50th anniversary + tourism is up after years of being down from 9-11. Guess it is possible that codes will be limited or they might be mixed in to a package (like free dining but you pay rack rate). I'd stay positive that odds are there will be codes.