The following two projects were undertaken as part of GSoC 2008:
Student: Mokhtar M. Khorshid Mentor: Julian Smart
The project unfortunately didn't achieve its goals and wxWallCtrl is still not available for the general use.
Fixing bugs in wxGTK and wxMSW
Student: Marcin Wojdyr Mentor: Vadim Zeitlin
This project was very successful, a huge number of bugs, including a lot of inconsistencies between the platforms, was fixed and a lot of unit tests added.