The Second Life 18th Birthday, or SL18B, is a little more than a month from now. So where are the sims? It looks like they're up, but most are still labeled SL17B from last year. Including the still unlabeled ones, there are a total of 22, though this could change. There's another sim called "SLB Dev" a little to the north of these, though is likely just a place for building things and not to be part of the exhibit.
The celebration will be held from Thursday June 17 to Thursday July 1, though the sims will probably be up for a few more days.
Stay tuned for more updates.