After coming up with the title I'm not sure if it means I would like it implemented or that it is already the case, but either way there are a few rather serious issues sucking the fun out of the dungeon finder. Particularly when it comes to heroics. The greatest of which is waiting 40 minutes only to have your group fall apart through no fault of your own.
In heroics I see a large portion of groups fall apart after a tank or healer, often with a DPS that queued with them, roll need on a piece of loot they wanted and then drop group immediately. It is obvious that they got a friend to up their chances of getting the item, came just for that and thought nothing of everyone else's time. Aside from that seemingly frequent special case most groups fall apart on any wipe, for any reason. Sometimes a bad pull that only a couple people die on is enough to have someone drop.
It would be nice to see the punishment for dropping a group be severe enough to give such players pause. My favorite idea so far is to have the deserter debuff longer (proportional to the frequency of dropped groups) and with stat penalties much like resurrection sickness. Including, of course, the loss of durability on every item the player is carrying. If dropping group is more costly than wiping a couple times then I'm sure people will try and make things work.
Of course we don't want to punish groups that really are failing. Each boss/dungeon should have a par associated with it. Something like this boss usually takes 3 wipes average for a group to learn it. If after those three attempts the boss isn't down then players can drop without penalty. Could even be something hardcoded, like 5 wipes over the course of a dungeon. Pretty lenient, but the goal is to get people to try rather than give up, not to force anyone to wipe on the same boss for an hour.
I'm pretty sure most players are in agreement that something needs to change and I think whatever solution is implemented should basically force people to put in a minimal amount of effort before giving up. Blizzard is collecting all that kick/drop information already so I can only imagine they will begin to use it for something more eventually. Right now it is just being used to throttle the number of people kicked, but not the number of people dropping as far as I know.