First of you got a few odd choices in your spec:
only 3 in Anticipation - you are a tank not a damage doer, so move those 2 in Viscious strikes.
Same with 3 points in subversion.
You can skip Dancing Rune Weapon - its does not improve your threat - its treated as a pet.
Also 3 points in imp. Blood tap can be better spent in imp ICY touch.
Since hit is sadly missing on a lot of tanking pieces you should also you 5 points in Dark Conviction.
I am going to change my own spec to: http://talent.mmo-champion.com/?deat...I,dOte-3,10952
(Changing to get Imp. Icy Touch over imp. Rune Tap)
Though probably changing my glyphs as well.
Single target: IT, PS, HS, DS, HS then I generally use what is available, make sure you have Runic Power if you are to interrupt target too.
Multible mobs: DnD, IT, PS, Pestilence, Blood tap, Blood Boil - then rotate around the targets, making sure to keep coming back to main target if marked.
A few things that can help you.
macro Rune strike to your abilities
/cast Rune strike
This uses runestrike when possible and that is a big threat boost, espcially with the 3.3 change to increase threat by 17%.
I am also using the addon called Aloft, this is a replacement for the default healthbar over mobs heads. What makes it imba is that you can set it to show a glow showing your aggro on mobs - that makes it easier to tank multible mobs as you can see by color change that someone is about to pull aggro on 1 of them.
I hope this have been a help.
Maybe check back to see what others say to my spec, havent had time to do much research into 3.3 changes, so may be using a talent wrong in a few places.