mind you if you do build qt4.7 from source
you will not be able to use any centos 6.4 rpm's that use QT
you might want to add an "exclude" QT command to yum.conf
to prevent any qt programs that need 4.6 from installing
you will have to also build those programs from source if you want to use them
there is "kde-redhat.sf.net"
from the cent wiki page for additional repos
it points here
-- but i have NEVER used it so ....