This is the implementation of the Ilshenar land mass, which can only be accessed with the 3D client. There are several new dungeons to explore, with some new, very interesting creatures to fight.
Two new tamables have been introduced: unicorns and ki-rins. I have had information in the pet database ever since I received my beta cd. During the UO Faire, one other creature was announced to be added with 3D: seahorses. However, these creatures have yet to be seen. There are a few areas in Ilshenar that can only be accessed by these creatures, as boats are not allowed in the new lands.
Some commands have been removed. Any "all" command with a target cursor has been removed, as well as fetch (which was disabled anyway), patrol, all release, and all drop. "[Petname] guard me" currently brings up a target cursor when it shouldn't. This is presumed to be a bug.
Bandages now weigh the same as cloth. Cutting a stack of cloth will convert it all to bandages. Very helpful for veterinarians.