How often are you tabbing? I know for most of the latter half of Wrath the AoE fest meant that I could forgo tabbing about with sunders and SSs, but that was wrath, this is cata; back to Tabbing every GCD that isn't a Shockwave or a TC tab around. In your ability list you mention HS, I assume you mean Cleave, If not, start cleaving rather than HSing when you have more than one mob you want aggro on.
I personally open with Shockwave as this generally lets me position the mobs without any pathing wierdness and is our highest AoE threat maker. I follow with Rend>TC>demo shout, popping Shield block as the stun wears off, procing revenge then SS, then Keeping TC and Rev on CD, tabbing with with SS/Dev/HT/CB and Cleaving like Saurfang on washday
Get fully enchanted/Gemmed/Glyphed. For AoE threat a Shield Spike is pretty nice.
I don't rate Blood Craze as a decent talent (post nerf), consider dropping points in it for ore threat if you don't feel too squishy.
How are you handling Inner rage, i find due to the nature of our rage dumps only hitting 1-3 targets that I prefer to use Inner rage before Dumping with Cleave or HS, especially in AoE as 15% more damage to SW/TC on 5 or so mobs outweighs a HS/CLeave. I'm lazy. I have IR macroed into SS, Rev and Dev, and a /cancelaura macroed in Battle Shout, Commanding Shout, Spell Reflect, and Shield Bash. It works for me, no doubt it will sound cLuNKy to some but I find it convienent to have an almost passive damage buff and simplifies the mechanic no end, I do track if its up or not with a PowaAura.
Also what exactly are you AoEing down? I recall a Blue Post from GC msaying something along the lines of "if its meant to be AoE'd down its probably going to be a hectic, and we don't expect the tank to hold aggro on everything, but we aren't going to have packs that need to be AoE'd need to be 100% tanked, becuase they won't hit like marrowgar"