Take special care and attention to the information below. A number of legacy access point models will no longer be supported past 8.0 code.
This is reminiscent of 1000 series access points. I can recall the horror stories, people upgrading to 5.0 only to realize that the 1000 series would not join the WLC. #DontBeThatGuy!
Ask your Cisco rep about buy back programs and bundle purchases; buy X and get 5-10 free access points!