Per ticket #25320, I'm about to submit fixed to bring qt4-mac up to 4.6.3 and qt4-mac-devel to 4.7.0b1; those updates are relatively simple, and in the process I've also created a 'qt4_select' so that all qt4-* ports behave nicely together.
Moving from the current version of qt4-x11 (4.4.3_5) even just to 4.5 requires significant changes in the Portfile; ditto for 4.6. I quickly ran into issues getting 4.6.3 up using just X11.
So the first step in updating qt4-x11 is I'm moving it to use 'qt4_select' so that it plays nicely with the other qt4-mac-* ports. Once that move is finished, I'll resume my efforts to get qt 4.6 running on x11.
I'll post back here once qt4-x11 work with qt4_select.
