The next version update is scheduled for a Tuesday, September 9th (JST) release.
Final Fantasy XI Director, Akihiko Matsui posted an outline of all of the content that will be included in the update, as well as the content originally scheduled for it that will be slightly postponed.
The two major highlights include Incursion, an instanced event against the Velkk beastmen of Ulbuka that increases with difficulty (and rewards) with subsequent progression, and Walk of Echoes surge and endowed modes.
Other items include job adjustments, Goblin box daily reward revamp, and some interesting UI enhancements such as: party sort, /itemsearch, and map icon additions. Matsui’s original comments can be read here.