In parallel with 3.0.x releases, we will start working on 3.1.x development releases (with 3.1.0 planned for fall 2015) which will eventually result in 3.2.0.
The main goal for this 3.2 release will be wxAUI refactoring/rewrite with full support for dockable notebook pages.
http://trac.wxwidgets.org/ticket/9419 https://github.com/redtide/wxWidgets/tree/aui-dynamic-notebook
wxAui rewrite planned in 3.2 http://trac.wxwidgets.org/wiki/Roadmap:
(emphasis mine)