Tanking stat changes in Cataclysm

With the Light as his strength, Gregg Reece of The Light and How to Swing It faces down the demons of the Burning Legion, the undead of the Scourge and helps with the puppet shows at the Argent Ren Faire up in Icecrown.
Since paladins are last on the list for the upcoming Cataclysm class previews due to how Blizzard ended up doing the development schedule, we've got another week and a half to wait for our details. I'm not picky as long as it gets done, so there's no reason to really grumble other than having to wait an extra week. However, I thought I'd go over some of the things we do know about Cataclysm for tanking.
Blizzard has mentioned that they're going to rethink tanking cooldowns and has previously asked for feedback on some of the abilities we currently have -- but to what end, we're unsure at this time. What they have told us about thus far is how some of the avoidance stats will be working in the coming expansion. Essentially, the only avoidance stat that isn't changing is dodge, with the others either being overhauled or removed. Let's take a look.
Reaching uncrittable in Cataclysm
First off, your defense rating stat is going away completely. That means the annoyance of trying to balance gear, gems and enchants to reach that magical 6% critical strike reduction (currently, 690 defense rating [edit: which is 540 defense skill and yes, 689 defense rating is tossed around as the number, but according to some theorycrafters, you really need 689 and change which means you have an absurdly small chance of being critically hit at just 689 which is why I said 690]) also goes away.
While things aren't completely finalized, Blizzard has said that they will likely just make it so that having Righteous Fury up will automatically make you ready for tanking both dungeons and raids, as far as crits are concerned. Each of the other tanking classes will have a similar, simple mechanic for this. Druids will have it baked into Dire Bear Form instead of the current talent Survival of the Fittest, warriors will likely have it tacked onto Defensive Stance, and death knights will add it into Frost Presence.
Higher health, lower damage, more hits
As far as stat scaling goes for the coming expansion, Ghostcrawler has been letting everyone know that health pools should be a bit higher than expected. That's nice, because bosses are going to hit for less but hit more often, much like some of the bosses in Icecrown Citadel. Oh, and your avoidance stats will be in the toilet compared to what they currently are, to avoid what happened in both Sunwell and Icecrown Citadel.
You'll be doing fewer dodges, parries and blocks than you currently are, as Blizzard has more or less stated that tanking avoidance stats have probably started out too high for the past two expansions. So instead of staying block-capped most of the time, you'll be sitting at a lot less than 102.4% avoidance for most of the expansion. How much less? We're still not sure, as Blizzard has only been hinting at the details of that.
All in all, you'll probably spend more time around 50% health while tanking than you currently are, due to healing's also being reduced drastically. However, you'll be in much less danger of being instantly killed while in that scenario, due to the less-potent boss damage. All in all, it should make things a little more interesting and less of a twitch-gaming scenario.