I've copied this in from my WoW Europe forum entry. As it was in Europe, no developer will see it but I think it adds something to this discussion.
I recall a recent trade discussion talking about merging Horde and Alliance in the same groups to reduce queue times. If you think that sounds ludicrous, it's no worse than going up against your own faction in a rated BG. I suppose the question is what's more important to you; doing your dungeon quickly, or immersive faction-related gameplay. This of course relies on the assumption that one faction has more tanks than the other and, personally, I cannot see any way in which that would be true.
As it turns out, I'm in the queue every day and have been for a while (only recently unguilded) - as mentioned, it takes longer to form a guild group in most cases when you're a tank, and I'm now at the stage where I can cover for almost any level of bad play and/or stupidity that I come across in a PuG. The only thing I can't handle is someone who is being deliberately difficult, but that's what vote kick is for.
As has been noted, the problem here is the lack of tanks - I strongly doubt that's a secret to anyone. The reason for this isn't so obvious, though. Some argue it's because of bad PuG players; some argue it's because of guilds; some argue it's because of the difficulty of tanking. I'm not sure I subscribe to any of them because there are counter-arguments to each one as why the number of tanks could go up.
Personally, I think it's because there's literally no reason for raid tanks to queue. Valor points are accrued in raids and the Valor gear itself is no better than what's available from the easiest of bosses in those raids. Once you've grabbed the items you want, tanks stop joining the queue because there's literally no reason to. Again, I know this because I've done it - I can't be bothered doing the same instances each day when there's no actual value in Valor points. When you add that to the fact Valor points become Justice points when a patch drops (and you can only have a stupidly small amount of Justice points), you're removing the need for a tank to queue once he's got everything from the vendor.
Compare this to most of WotLK when the higher tier of vendor gear was better than what was available in 10 man raids. This meant that the multitude of 10 man tanks would still queue because they wanted every piece of gear they could get from the vendor. The solution, therefore, could lie in beefing up the vendor gear by a few points and increasing the average price of them. This would make the gear itself more desirable, but would also keep tanks queuing longer because they'd need more points. The only significant downside is the impact on casuals who can only get their gear from the vendor, but I'm not sure what you'd need high-end raid gear for if you're only doing a few level appropriate heroics.
I also have a confession to make; if I were a DPS or healer by trade, I'd be terrified by the proposed changes coming in 4.1 (reference the first 7 dungeons give Valor points). I know it sounds great not having to log in every day to do a heroic, but think of the impact if you're a tank. The first night you're not raiding, say Friday night, is the ideal time to sprint through your seven heroics and then you're done - no more queuing on any other night of the week, which means far less available tanks at any given time.
Time will tell, but I worry that Blizzard is about to make the dungeon queue times a whole lot worse if this change is implemented.
Of course, don't forget - those who have outgeared the launch heroics will only start queuing for ZA and ZG - this may actually make tank queues shorter due to more players being willing to try heroics in an environment where they're not horribly outgeared and, thus, have limited chance of success.
Just a thought.