Technically, there needs to be a level 2 judge to run a prerelease. I know they have made exceptions, but the "floor rules" or whatever the documentation that govern this is states that you need a level 2.
That's why we were fairly sure that we would still be able to have a prerelease in Portland, but you can't just say you are going to run it. WotC has to sponsor you or some such like that. Our best guess is that they didn't want to just have a prerelease but rather a group that could run all major events.
From talking with Ken Horton, who used to run the Portland/Eugene events, the prerelease is the big money maker as events go. He says that most organizers do the other events just so they can do the prerelease also.
Its also possible that they just got really busy. My wife helps WotC with translation and I know that the guy who coordinates the organizers was just put in charge of the translation groups as well. If that is the case, we may be able to get things taken care of in time for the next prerelease in October (late September?).
