Hi,
Bitcoin-qt is now feature complete (including wallet encryption), and has been tested for a while by various people without any major problems.
It is now in status of feature freeze.
The project builds on Windows, MacOSX and Linux using qmake.
Impact to the core bitcoin functions is still minimal, and it can co-exist with Wx in the source tree. The only thing it lacks compared to the Wx GUI is translations, currently we only have English, Dutch and Russian.
So IMO, it is ready to be merged.
JS