A port of the wx gui is now available in hg tip. It's a fairly straight port, most stuff is there except the network tab.
When it's functionality complete I will refactor it to make it more OO/Qt-ish. Then we can start discussing changes for 0.7
As it's still a WIP it's not built by default, excecute 'make luxrenderqt' to build it.
In time the idea is that it will replace the wx-based gui, which has grown to be a PITA to build on some platforms (especially on mac).
Edit: thanks to Cperrin88 for helping out a n00b with Qt Designer