Miraculously, the 2009 Annual Report is now on the web: http://www.eaa.org/about/2009annualreport.asp so you can draw your own conclusions.
The way I read it, regular membership still declined in the 2009 fiscal year:
Membership Dues & Subscriptions: $5,759,046 vs. 6,227,621 last year.
Publishing and Member Services rose: $8,591,961 vs. 8,399,343 last year. So it appears membership is a loss leader.
Donations are still a huge part of income, almost double Membership Dues, but declined by a million dollars.
Investment income recovered pretty well in 2009.
If Admissions and Registrations is mainly from AirVenture and the Museum and AirVenture Expenses are spelled out, looks like EAA made about a million dollars on AirVenture in 2009.
All told, it looks like maybe EAA should rebrand themselves AirVenture, Inc. because it appears that is where the money is, not in the membership.