Had a look and didn't find this, so thought I'd suggest it.
It would be nice if you, as a wannabe party leader, could open up a window that had 7 slots (for example), and in each one you could select a few things, like primary profession. Then, players who are looking for a party could call up this window and see all the parties that are after their primaries, and join them. The party leader could even put notes in, saying "after echo nukers", "air spikers", "protection monks" etc.
I think that although it would make arranging parties more complicated, you'd end up with balanced parties far more often.
Also, this is in addition to the current system, not to replace it.
Party creation window/Interface
AaronSwitchblade
Spoony
It could work something like, when you highlight the blue shadow with the current number in a team, you could there write who you need. Of course, there should be a limited number of digits allowed, and no f**k's and s**t kinds of words there.