Next year will be....interesting.
Indeed. A mass exodus is the trend for teams that win it all. College kids don't have much interest in defending a championship. They did it once, and they felt like they've accomplished their collegiate goals - and they're ready to move onto a new goal. You should still feel sky-high for the next 12 months or so, even if you barely make the NCAAs. The next year is about gloating and milking every minute of the championship until someone else wins it all.