If you try to install, even with Homebrew the latest version of Qt the 4.8.x, you may end up haing a surprise like that :
ImportError: dlopen(/usr/local/lib/python/PyQt4/QtWebKit.so, 2): Symbol not found: _kCFWebServicesProviderDefaultDisplayNameKey Referenced from: /Library/Frameworks/QtWebKit.framework/Versions/4/QtWebKit Expected in: /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
This is coming precisely from a Qt issue that don’t seem to be resolved anytime soon, so anyway you’re warned now, revert back to 4.7.x you have no choice. Except if you want to buy Lion 🙂
Vale
O. Girardot 
Hi Vale,
Today, I was compiled the source Qt Library 4.8 package on 10.6.8, and it just works! It’s not required to buy Lion 🙂
Seems the .dmg downloaded from offical site is compiled on 10.7.
Compile with default configuration took 6+ hours on my MBP, and 2+ hours with:
$ ./configure -release -shared -opensource && make -j4