UPDATE: New post for the new packages: http://joseph.freivald.com/linux/2010/06/09/qt-4-6-3-and-qt-creator-1-3-1-1-updates-for-centos-5-5/
The Qt4 packages for Centos are updated to 4.6.2 and Qt Creator is updated to 1.3.1.
To install:
rpm -ivh http://software.freivald.com/el/5/i386/os/software.freivald.com-2.0.0-0.el.noarch.rpm
yum update fontconfig fontconfig-devel qt4 qt4-devel qt4-doc qt4-postgresql qt4-odbc qt4-sqlite qt-creator
Verify that the versions are coming from software.freivald.com and enjoy. 