Pre-order Aion?

Aion is finally almost here. I have been looking forward to it for almost a year; I actually had it pre-ordered last October. But, in the interim, I have sworn off pre-ordering hot new games. I have just been burned too many times in the past couple of years; I pre-ordered Pirates of the Burning Sea, Age of Conan, and Warhammer Online and suffered crushing disappointments. My resolution was recently tested with the release of Darkfall, but vindicated when my guild's division flamed out in less than two months due to game play issues, saving me the cost of the game.

I am oh so tempted, though. Aion is an NCsoft product, and NCsoft also published Guild Wars, which is the best MMO I have ever played. I canceled my Warhammer subscription in January, and I am suffering severe gaming withdrawal. Aion won't be out until September, but if I pre-order now, I can play the US betas. The next beta starts Friday, so I feel some pressure to decide before then. After all, if I am going to pre-order, I should get all the beta joy I can out of it. I also cherish a hope that, should I try the beta and hate it, I can cancel my pre-order.

Several people in my guild have been playing the Chinese beta and love it, but none of them are people that I know from other games, so I'm not sure how much weight to give their opinions. After all, I know people who love playing Eve Online, but that doesn't make it a good game. Ten Ton Hammer gave the first NA beta event a favorable review, but they didn't get to try any PvP.

What do you think? Should I give in to shiny beta temptation or wait a couple of months after release to see if the game actually has legs?