Nice.
I set my build system up, so that I have the original mingw-compatible .a Qt-libs for release and msvc-compatible .lib libs for debug. I wouldn't have thought this would actually work without conflicts. I wrote a small cmd-line script to compile the release builds with a double-click on a desktop-icon, while I develop&debug with Visual C++ 2008 Express.
I can really recommend this combination for Windows Qt developers ^^
I just added ROM file selection, basic validation & loading code to the Qt build.
EDIT
I made changes to the rendering system.
It will now use either OpenGL or QPainter, depending on what is available.
The smart thing is that I can do everything with QPainter and Qt will translate it to OpenGL calls.
One issue in Qt is the timing. Even though I create a 60Hz timer, I only achieve about 40fps. But with idle time processing (timer interval 0) I get over 1000fps, so it should be possible to build something on top of that.
We'll also have to look into the Threading possibilities of our emulator.