Forget about the clunky mess we have atm, it's semifunctional garbage not meant to be used by the public.
Instead I contend we get a craigslist esque setup. It can be automated, sure why not.
For the general outline, I'm thinking you select what your grouping for: quests/dungeons/trials/pvp/whatever. You select weather its open or closed. (open being you can land into it by grouping for anything, wheras closed would allow the group leader to screen for players.
This has key advantages: You can que for open groups for a fast run/find and do whatever. And for those that want to take their time finding a good group they can do that to. something for hardcores, and something for the more casual, laid back crowd.
A grouping ban would do better in this situation, as you're queing foe pretty much anything you want.
A couple addons I'd like to see included would be a browse feature. Something l=so you can look at what groups are open and be lije hey that looks fun.
Then a note section just below whatever yoh;re cuekng for. 'need pro players for nodeath run' , 'trial leaderboard scores', 'helmet farming', 'casual play' , 'learning wgt', 'sewer farming'. Anything.
Then allow the cue creatoe to select what roles they want. Be it, 4dps, 3dps and a tank, 2dps 1 healer 1 tank, anything. If you want a tankless run for speed, you can do that without screwing other people over.
basically, when using the interfacem you select what you're making a group for, what roles you want, a side note about the group, and bam.