Looks good... Here are a couple things I noticed.
Helm Meta - Get the one 10% shield block!
Spec... Not sure if I totally understand what you are going for here.
*You have wasted alot of points in the Arms tree without getting deep wounds.
*Go get armed to the teeth (especially if you are going to keep the meta gem!!!!!!)
*You don't need Puncture... Devastate more.
*You probably don't need gag order... Unless you are prot pvping.
Overall I think you would enjoy tanking even more if you went and got Ciderhelm's deep wounds spec. I promise it is awesome as an MT or OT.
Shoot me any questions