So I woke up to the big news today that Blizzard is finally implementing a suggestion that I've seen people make on various blogs many times by now: that tanks and healers should get greater rewards for using the dungeon finder in order to shorten queue times for damage dealers. In practice, the system will "only" reward players for filling the role that is the most needed to create a max level heroic group at any given point in time. In 99% of all cases this will be the tank.
I'll be honest, my first reaction was: "Cool, I guess I'll have to go back to tanking heroics on my druid and paladin once the patch comes out." However, then I spent a minute remembering all the things that have pissed me off about my heroic pugs in the last couple of months and quickly amended my thoughts to add "...but probably not for very long". I strongly suspect that this is what will happen on a large scale as well.
In other words, I do think that this new system will work in the short term, as players will queue up as tanks whenever possible simply out of curiosity, to see what this new extra loot bag is all about. Once the possible rewards become widely known, people will still make a point of queuing as tanks for a while, in order to chase that special mount they always wanted or what have you.
However, in the long run, I predict that people will quickly realise that
1) whatever the reward, tanking itself is still the same as before and if they didn't enjoy it already, they are still not enjoying it now.
2) they really prefer tanking for their friends and guildies, but the Call for Arms system only rewards them for queuing alone. Wasn't this supposed to be the expansion that encourages playing with your friends again?
3) they've got everything they wanted and whatever special rewards are left for them to attain aren't worth the effort. (Flasks and gems are useful, but unless the system gives out massive amounts of them for each run, running heroics is hardly going to be the most efficient and painless way of acquiring them.)
And thus the queue times for dpsers will get longer again and we'll mostly be back to where we are now. Eventually more people will choose to tank again simply in order to get the shorter queue, as heroics become easier again - just like we saw in Wrath - but this might take a while and will happen independent of the Call to Arms system.
I'm not annoyed with Blizzard for implementing this and will be curious to see how it pans out. I'll be happy if I'm wrong and it works as intended, but I just don't think that will happen. Bribes are not useless, but they only go so far. Not to mention that I believe that they are what caused this whole queue problem in the first place. How many damage dealers that are clogging up the heroic queues actually dislike instances and group play and are only in there because it's the only way to progress your character past a certain point and the dungeon finder allows them to participate without actually having to talk to anyone? I think it's very telling that Bashiok revealed at the end of his statement that lower level dungeons don't suffer from dps overload in the same way - it's because people have alternatives while levelling, and the Satchel of Helpful Goods you get for running low-level randoms is not so great that it's worth getting if you don't care for instancing in the first place.
The bottom line is that I think that the developers need to take a step back from making everything about item incentives and think more about making sure that players actually enjoy what they are doing. Yes, you can lure them into doing things that they don't actually care for - see all those damage dealers in the dungeon queue. But the only reason that works is because a lot of the time, dpsers can get away with playing in a group in the same way as they do while soloing (or even worse, because the tank and healer are there to protect them), so they still get to play the way they want even with other people around. Tank play is quite different on your own compared to in a group though, and when it comes to choosing between extra item rewards and playing in a way that's fun, players won't be willing to chase the carrot quite so readily.