I ran a complete upgrade last night using /usr/ports/ports-mgmt/portupgrade. Updated everything I have installed.. well over 700 packages (of course some didn't need or have updates). Granted, it took a full 24 hours and several trips back to the computer to adjust config settings, it worked flawlessly and KDE 4.3.4 is installed correctly without hiccups (as well as fluxbox, xfce4 and a multitude of user apps).
From the command line, simply do `portupgrade -a`. On another note, the -P flag seems to incorrectly fetch new packages from FTP as it added version numbers not normally found when using pkg_add -r.