Midnight showing is the way to go. Every major movie I've seen over the past few years (x-men 1 & 2, spider-man 2, LotR trilogy, AotC (was too young when TPM came out), Matrix reloaded/revolutions, etc), and I love it. Nothing beats how full of life the theater is at a midnight showing. Even if the movie sucks, no one cares. The excitement of the other moviegoers is almost tangible. When something cool happens, the whole theater starts cheering. When a character dies, everyone goes quiet. The theater is full of fans - people who are as excited about the movie as you are - and they're all seeing it for the very first time with you. You see a movie any other time, and it's just... boring. The theater is quiet, there's very little excitement, there's usually people talking or complaining or getting up in the middle of the movie... The only thing going for it is the big screen. If I wanted to see a movie like that, I'd rent it on DVD and watch it at home.
The showing of AotC was perhaps one of the most fun movie experiences I've ever had. Half the people there were in costume, and while we were waiting, a bunch of people in Jedi outfits went up on the little stage area infront of the screen, and started dueling, and then like, all the other jedi in the theater went up and joined them, and soon there was an entire mob of people swinging glowing sticks at eachother. People would get hit and play out mock-death scenes and roll off the stage (... and then get back up and start fighting again), and it was just... fun. It was stupid, it was immature, and it was nerdy as hell, but no one cared. Everyone was just there to have fun, and I don't think that there was a single person in the theater that night that didn't.
As for camping outside the theater for weeks on end... That's a bit much. I can't say I blame them, after all, this is the last chance they'll get, and we've all been waiting for this movie for years... But camping out for weeks is a bit too fanatical for my taste. But to each his own, I guess.
Moo.