Make it easier for amateurs to practice; possibly through community boats / club boats / fellow member boats... Launch a AWSA Community Boat Drivers Program/License that backs boat owners, drivers with liability coverage and can help them connect with those that don't.
Community outreach possibly through Cub Scouts, Girl Scouts, Summer Camps, Colleges...
Fully embrace Wake Surfing & Wake Boarding (doing a decent job already) to reverse engineer / bring full circle the awesomeness of Slalom along with the newer sports.
Improve cool factor through promotion of Pro Events. Possibly a Red Bull TV Documentary? Sounds stupid but in college I got a very nice AWSA Decal pack with my membership; I rocked it on my car and family boat with pride then and it pulled in a few new members and made be feel cool. Maybe 1st year members get a Decal Pack and 2nd year members get a shirt...