Or you know, crazy idea here, 8 man parties that just need 1 tank, 1-2 healers, and 5 players that are either pure dps or dps/support hybrids.
Oh wait, we have that. ....Just not in abundance.
Now, I would like to see them add some support classes to be honest. Yet in order to add those they would have to either make them dps hybrids so that parties don't lack on dps when you have more than 1 of these support type classes, or make a healer that is a support hybrid with not only buffs but debuffs as well. (Doesn't Sch kinda fill this role?)
I dunno. I just don't see it actually happening. Not with how the ARR team as shown us the kinds of dungeons they are making. In my opinion very few of these dungeons actually qualify as a dungeon. They may be sections of some that feel large, but ultimately they are just narrow paths we follow... and not even very long ones at that.
I would like to see a dungeon that requires players to sit down and take a good hour or more to complete, but seeing as ARR is pretty much built for the casual crowd (not completely a bad thing) I don't see this happening. The longest Instances in the game right now are pretty much just LotA and ST which, depending on the quality of players in the instance, can run anywhere from 20ish to 45 minutes with no full wipes. The only reason it might actually take longer is if there are a lot of bad players or new players who don't know the mechanics and several wipes occur. Deaths/Wipes are the only thing that prolong dungeons. A normal dungeon (even the coils, once the mechanics are learned) take only about 15-30 minutes to clear.
It's all so quick and brief. More like a roller coaster ride than actually delving into some unknown dungeon.
I don't personally mind it too much, but a longer, much bigger dungeon, would be nice. More mini-bosses, more loot, same dungeon. Larger areas.
ST does a pretty nice job of aesthetically making the platforms you fight on appear quite large, but every single room is exactly the same basic shape. Though I can't really complain about ST too much since you are working your way up narrowing tower.
Hopefully though with future 8-man "raids" they give them more of a dungeon feel. Praetorium is probably the closest thing to feeling like a lengthy dungeon done right, with exception to the last bit of it as you are just teleported from once platform to another, and then you use the same platform for 3 bosses (technically just 2). Specially if you were a new level 50 running it in your AF with others that were in just AF or a few pieces of Darklight. I dare say that it was actually a bit challenging back then (though Lahabrea was still pretty much a pansy).