The old question of whether to gear for survivability or whether to gear for threat is usually the first a new tank, or any tank entering new content, will ask. Essentially, the only answer that fits all situations is: what do you need? If you're dying a lot, survive more. If threat is a problem, work on that. What is most important for any raider is always to live. If you are dead, you cannot tank, heal, or dps. So for entering new content for the character, survivability is king. That means stamina, armor, dodge, parry, mastery. Luckily for tanks, stamina is becoming more of a threat stat as well due to Vengeance. Obviously it relies on being hit often and hard, but it will help. Only once dying is no longer a constant danger should it occur to a tank to start gearing for threat. Obviously your fellow raiders will be getting gear that noticeably improves their dps and therefore their threat, so a tank, in order to not get yelled at by his fellow raiders, must gear accordingly.
It seems a lot of tanks, warrior and non, have been having trouble with their threat. More so than before the patch, anyway. The solution to threat is part gear adjustment, part personal adjustment, and part happy joyful world where everyone waits until you have threat to dps. The last part isn't going to happen, although a good number of my guild mates imagine a world where all the "gogogogogo" people have quit WoW due to the slower pace of the dungeons, I don't see that occurring at all. People are the way they are, and slowing dungeons down will merely make them want to go even faster so as not to waste any excess time. So the burden lies upon you.
The first step is to find a 2.6 speed weapon. This is because due to the lack of "on-next-swing" attacks, the speed of our weapons no longer matter, and since a good deal of our attacks are reliant on our weapon damage (most importantly for us Rend), a slow hard-hitting weapon is perfect for us. All tank weapons in Cataclysm will be 2.6 speed, but for now, I'd recommend picking up something easy like Wrathful Gladiator's Cleaver since it no longer requires arena points. It's not strictly speaking a tank weapon, but until the expansion is released, it's a solid threat producer.
Second, make sure you are hit and expertise capped. The current expertise cap is 23, but will be 26 again at 85. Reforge if you have to. Nothing will make you lose aggro faster than a missed hit.
Third, I'd like to address a lot of people's concern with the Rend/Thunder Clap combo. It seems from reading various forums that people find it "lackluster", "awkward", or just plain terrible. I've given it a lot of thought and there always seems to be a few things in common with these complaints. A lot of them haven't taken the steps necessary to really take advantage of the ability. Many of them haven't utilized the new 2.6 weapon speed, which changes Rend's damage significantly. Several of them have terrible hit rating. Others complain that as they Charge in, then Rend, they must wait a whole GCD before they can do anything and then they lose aggro. This has a lot to do with the fact that people don't seem to realize that abilities like Cleave are off the GCD. The proper way to pull is more like Charge, Rend/Cleave, Thunder Clap. Obviously starting from dry this isn't always possible, so start out with a shout before the pull. Others complain that even charging in will pull people to the healer immediately. Personally, I think that's a problem with healer aggro having gigantic radii since the patch, but if it's a problem, take Blitz (which any 5-man spec should have) and you'll be stunning three targets as well as gaining a lot of early rage. The point is, the Rend/TC combo is a fantastic ability that gets even better the longer the fight lasts. People just need to learn how it works, rather than try it once without proper preparation and running to the forums to whine. I read one forum goer who complained that he didn't like it because his Rend was in an awkward position and he had to move his hand around oddly to get it. MOVE THE KEYBIND NUMB NUTS!
Survivability is easy and usually just a matter of gear. It will come in time and eventually be a non-issue. But until it is, it is without a doubt the most important thought in a tank's mind. With how the developers have claimed Cataclysm raiding will go, the healers will be under less duress to pop out insane numbers to save you from instant death, which means it may even be something obtainable rather fast. Threat is where the tank's resources will be focused on constantly I believe, and it will be important as you level to 85 and in these remaining few days before the expansion to cultivate good habits and practices. By abandoning Rend/TC, a lot of tanks are getting rid of our only effective method of AOE tanking, something which a lot of warriors have whined incessantly for years for. Blizzard finally gave it to us, and I love it.
On a side note, I am really really disappointed in how my all-time favorite ability Vigilance has been treated this last patch. In 4.0.3a, Blizzard removed the 3% damage reduction from it, and made the ability go from awesome to just another ability. While I will be keeping it for my raiding spec, due to how valuable constant tank taunting can be, as well as the free stacks of Vengeance, it has lost it's heart. The reason Vigilance was so amazing was not because of its 3% damage reduction, but because it had 3% damage reduction and infinite taunts and Vengeance. The combination of all three in a single buff was ridiculously awesome. With only two now, any two, it has died. It's just another ability now. Not bad, but not great either. I don't approve of the tank homogenization. I am a warrior, I don't want to be a paladin 2.0. Well, rather, I don't want paladins to be warriors 2.0.
