emerge -DNu -1pv world causes Calculating dependencies... done! [ebuild UD] x11-libs/qt-4.3.3 [4.4.2] USE="accessibility%* cups%* dbus doc%* gif%* jpeg%* mng%* nas%* opengl png%* qt3support sqlite%* sqlite3%* ssl%* tiff%* zlib%* -debug% -examples% (-firebird) -glib% -mysql% -nis% -odbc% -pch% -postgres% -xinerama%" INPUT_DEVICES="-wacom%" 0 kB [uninstall ] x11-libs/qt-assistant-4.4.2 USE="webkit -debug -pch" [uninstall ] x11-libs/qt-xmlpatterns-4.4.2 USE="-debug -pch" [blocks b ] <=x11-libs/qt-4.4.0_alpha:4 ("<=x11-libs/qt-4.4.0_alpha:4" is blocking x11-libs/qt-xmlpatterns-4.4.2, x11-libs/qt-script-4.4.2, x11-libs/qt-dbus-4.4.2, x11-libs/qt-assistant-4.4.2, x11-libs/qt-qt3support-4.4.2, x11-libs/qt-sql-4.4.2, x11-libs/qt-gui-4.4.2, x11-libs/qt-svg-4.4.2, x11-libs/qt-test-4.4.2, x11-libs/qt-core-4.4.2, x11-libs/qt-webkit-4.4.2, x11-libs/qt-opengl-4.4.2) [blocks B ] x11-libs/qt-core ("x11-libs/qt-core" is blocking x11-libs/qt-4.3.3) [blocks B ] <=x11-libs/qt-4.4.0_alpha:4 ("<=x11-libs/qt-4.4.0_alpha:4" is blocking x11-libs/qt-xmlpatterns-4.4.2, x11-libs/qt-script-4.4.2, x11-libs/qt-dbus-4.4.2, x11-libs/qt-assistant-4.4.2, x11-libs/qt-qt3support-4.4.2, x11-libs/qt-sql-4.4.2, x11-libs/qt-gui-4.4.2, x11-libs/qt-svg-4.4.2, x11-libs/qt-test-4.4.2, x11-libs/qt-core-4.4.2, x11-libs/qt-webkit-4.4.2, x11-libs/qt-opengl-4.4.2) Total: 1 package (1 downgrade, 2 uninstalls), Size of downloads: 0 kB Conflict: 3 blocks (2 unsatisfied)
just mask qt-4.3.3 :) KDE-4.X works with qt-4.4.X