The big changes are to the guild window, knowledge book, some inventory, persona window, and some map window changes already added to eq2map. Otherwise its just small tweaks and such to many of the other windows.
The tool tips for the spell mouse overs have changed alot and many graphic icons have been added as a result. Also new ofcourse is the arena xml, they pushed alot of it to live a month ago but it has all changed.
Here are some pictures, I havent gotten pictures of the changes to the bank window yet:
Arena windows
Guild Bank windows
Persona window
Spell Tool-Tips