Once again, I took a couple of my toons through some Timewalker dungeons. I only ran one a piece on these guys, but that gave me enough to have a general impression.
Let's start with Brewmasters, as I've spent a lot more time (or at least more time recently) tanking as a Monk.
Brewmaster's focus is SIGNIFICANTLY shifted. While you'll still be dodging a lot thanks to the new mastery, they've really focused things on the Stagger Mechanic.
Ironskin and Purifying Brew are generally available without too much trouble - you sink your Energy into Keg Smash (which still does more than half of your damage) and Tiger Palm, both of which speed up the recharge rate on your brews.
The main challenge is that they share charges, so while you might want to maintain Ironskin Brew at all times, that will make it harder to have Purifying Brew up for those emergency moments.
Especially with Ironskin, you're going to have higher amounts of stagger than you used to have, so you really do need to make a choice between these guys.
Gift of the Ox, which is now what allows you to use Expel Harm, seems to happen way less frequently, so self-healing is down. The loss of Guard, though, is really the huge nerf - that thing was absurd.
The only really annoying thing about the Brew mechanic is that between pulls, you might be low on Brews and have to decide whether to stop to let them recharge or start the next pull with low booze supplies.
Still, remember that all tanks got their survivability nerfed, so it's not just you.
Threat and Damage:
The pull is going to be tricky. You no longer have Dizzying Haze, so you'll either need to Roll in and Keg Smash or use Crackling Jade Lightning to grab one guy's attention and then try to pick up the other guys.
Breath of Fire is now much easier to slip into the rotation, and you've got Blackout Strike as a filler when you don't have enough Energy for Tiger Palm (or want to save it for Keg Smash.) I did have a Prot Warrior pretending to be DPS in my group, so I suspect that my threat was fine even if he kept peeling adds off me.
You're going to be relying a lot on Keg Smash for your AoE threat. You can talent into Rushing Jade Wind (it might have a slightly different name now) and other talents like Invoke Nizou, the Black Ox or Black Ox Statue will help, but none of this is baseline. You really just have Keg Smash and Breath of Fire.
Monks are still quite mobile, with Roll and Tiger's Lust if you have that talented. This hasn't changed too much.
Ok, now let's move on to Druids.
First a caveat. While my Paladin and Monk have been mainspecced tanks and my Death Knight has tanked on and off (including some LFR HFC,) my Druid is one of my least-played classes, and the last time I did any serious tanking on the Druid was probably in Icecrown Citadel. So bear with me here (that was honestly not meant to be a pun.)
This felt actually about on par with the Paladin. It got a lot better when I realized I had swapped the positions of my Maul and Swipe buttons (they're similar icons, ok?) so that I wasn't spending my Rage on Maul when I was trying to pick up adds.
Ironfur is probably going to be your main Rage-spender, especially because multiple applications stack (though it's Ignite-style, so the first stack will expire as normal instead of getting extended, because that would get absurd.) You will occasionally need to use Frenzied Regeneration to heal up when you get low, but I never felt like was totally out of charges on that ability, and at 10 Rage, I didn't ever feel I couldn't afford to cast it.
Damage and Threat:
Given that Thrash is a Rage-builder and is used in single-target as well as AoE tanking, threat's not terribly hard to come by. Between Thrash and Swipe, you're going to have an easy time getting groups of adds to pay attention to you.
One odd thing is that you now use Moonfire. I think you're going to want to DoT up at least your main target but also probably every target with it, though obviously you want to use the Rage-generating Mangle and Thrash on cooldown over Moonfire. The great thing about Moonfire though is that it's a good pulling ability and can quickly be applied to multiple targets.
You can talent in some mobility - Wild Charge works really well - but baseline you pretty much just have Stampeding Roar, which is more of a raid cooldown.