Looks like the much-anticipated (at least by myself and pretty much everyone else except Peter Sciretta) Serenity will get its world premiere at the Edinburgh Film Festival in August. Of course, this doesn't count the cross-country sneak peeks that were held. This is the official premiere. Tickets are available to everyone, not just press. Creator/writer/director Joss Whedon himself and most of the cast are expected to attend.
If the powers-that-be see fit to send me oversees to cover this, well, that's a bullet I'm willing to take. For the sake of the readers, of course. I'm a giver.