I'd like to echo the law issues, and really point out the "more than 1 club" aspect needed to hold the event.
Laws relating to alcohol are often asinine. It's even worse when you bring home brew into the mix. Then, throw in homebrew transportation crossing state (or even NATIONAL -- ask the Vancouver BC guys about bringing homebrew to NHC) borders, and you get a perfect storm of pedantry and "How dare you?!?! You are but a lowly subject, you heathen" BS.
But it really took a group of us forming our "club of clubs" -- WAHA (Washington Homebrewers' Association) that made it a reality. We were able to get most of the clubs in the state to come together to plan and execute on that plan. Without everyone pitching in and helping, there was no way we could lobby to pass laws that enabled legal homebrew transportation, no way we could get all the committees manned, no way we could get all the big and little things done that brought the conference up to Seattle (well, Bellevue).
I made many new friends in that process, and remain close to them today, 7 years later. It's always like a little class reunion whenever we get together.