Never happen. I think it would be interesting but this community is TOO international and TOO spread out even U.S.A. wise. What would the draw be? I mean ppl paying money to go to some huge Nerd convention (Star Trek, Comic Cons, Anime Cons, etc.) makes sense. There's some tangible product to come away with. For us, most of us have the Neo or did at one time, it be more or less to meet one another right? Even I would be hard pressed to buy a plane ticket, bus ticket, or whatever... travel to some other state, go to a city I've never been to, only to have what would amount to a MASSIVE hangout.
None the less I'd be interested in going to one, but as already mentioned, there's the "plane ticket" problem. Many of us here are highly opinionated to the extreme (me included of course), and in a social situation, it could get stupid mighty quick, especially if someone was razzing someone and told to knock it off and they wouldn't just let it drop. This online community (while I love it) is a cesspool.
4 that reason I'm intrigued by the idea, but there should be like something to really make the whole thing memorable. Gun Range Day, xXxtreme Sports Day, Video Game Armageddon Day, Bros Pullin' Hos Night... a Drink A Thon, and cap it off with eating sushi on the raw (off of hot nekkid women). Basically a center we all meet up, but it's like a whole week of events where we'd all have to caravan or have multiple buses driving us around to various events. All in the name of camaraderie.
That's my idea anyhow.