This is the tracker bug for all issues preventing stabilization of the ~x11-libs/qt-*-4.5.2 ebuilds.
Errmmm sorry but Qt herd is the one who gets to decide which version of Qt will be stable candidates :) Qt will release 4.5.3 in the near future so there is no need to stabilize 4.5.2 . We have already a stable 4.5.1 Qt on portage Closing as WONTFIX