Qt 4.6 has been released (with some new features) so I've taken the opportunity to make sure my instructions on how to compile Qt with Visual Studio are still accurate. The additional steps on how to take advantage of your multi-core processor (using jom) still work, as well.

[Edit: Qt 4.6 actually has prebuilt binaries/libraries for Visual Studio 2008, which is preferable to spending hours building Qt]

I've made a note in the article but I'll repeat it here because it's a major time-saver: you should delete, from your Qt folder, these instances of mocinclude.tmp:

\Qt\2009.05\qt\src\3rdparty\webkit\WebCore\tmp\moc\debug_shared\mocinclude.tmp
\Qt\2009.05\qt\src\3rdparty\webkit\WebCore\tmp\moc\release_shared\mocinclude.tmp
\Qt\2009.05\qt\src\script\tmp\moc\debug_shared\mocinclude.tmp
\Qt\2009.05\qt\src\script\tmp\moc\release_shared\mocinclude.tmp

Deleting the first two mocinclude.tmp files will prevent a LNK2019 error while building Webkit, while deleting the last two (which are new in Qt 4.6, as far as I can tell) will prevent an Error: Unknown interface while trying to build qscriptextensionplugin.h.