I attended my first this past summer (Gallery Here
) and even being camped on the grounds for nine days, I felt like I barely scratched the surface.
With only two days, my advice would be to key in on one particular area (Warbirds, Antiques, Classics, Sea Plane Base, etc...) and milk it for all it's worth. Go early .. Stay late and work it, work it, work it...
Do a little walking around, take in some of the airshow in the afternoon but if there's one particular type of aircraft you really like, I'd expend most of my energy there.
If you're a fan of the DC-3/C-47, you're in luck as they're having a huge roundup of them in 2010.