Coming back after a two year break you are definitely seeing that tanking isn't at all what it used to be. I have played with a group of friends consistently and for the most part we've kept our group roles the same. But the game has changed a LOT (understatement) and that fact is creeping in to our playstyle. When we do group with people outside our circle we see exactly what the overall group game has become.
Groups need a tank for the tight spots but for the most part they don't need us at all. It seems everyone has decided that all-out DPS from everyone is better than managing a fight and taking it safe. As a "tank" your job ends about 2 seconds after the pull.
You'll take the initial barrage from the mobs and then nobody cares after that. A mage or scout will take aggro. You'll try to get aggro back but it won't matter. The healer is keeping up the DPSers and the mobs will be dead in a couple seconds. After a while you'll get used to the new game. You'll always be in offensive stance (except for difficult names) and try to keep your DPS up.
If you try to group with random people and tank "old style" you'll be berated quickly. You're too slow. They will start pulling more mobs. There is no such thing as recovery time between fights anymore. There is no downtime before a fight to set up a spot to tank from to avoid adds. There isn't any strategy (with a few exceptions).
Your job in 2009 is to pull, DPS, pull, DPS, pull, DPS. If you don't do that job quickly others will be doing to pulling for you. And frankly, most groups have enough DPS to not really care if you are DPSing or not. Your job is then to provide your handful of group-wide buffs.
In short, I play my guard when it's my turn. Otherwise, I'm more than happy to play my alts.