A few days ago, I started work on RC1 and here the results.
If you want to test QT 4.5.0 feel free to checkout and test.
Please note, KDE 4.2 will currently not work with QT 4.5.0.
Also, you should know it is experimental. Please build QT
with debug flags.

To get QT4.5 try

# svn co https://kf.athame.co.uk/kde-freebsd/branches/qt-4.5/

Happy Testing