Your proposed gear has an awful lot of hit and expertise gems. While these are valuable threat stats, you'll find your gear will be pretty well itemized for it as you go along. What kind of content are you planning on tanking in the near future? Are you currently experiencing threat issues with your dps?
Right now it's 90% heroics with an occasional 10 man OS. I run with a small group of friends, but we'd like to get into Ulduar/ToC 10 at some point if we can find more people.
I generally pull about 4.5 to 5k tps but I have a well-geared DW frost DK and Boomkin who are close on my tail most of the time on the threat meters.
I'm not exactly sure what to gem/enchant for, other than to keep my defense above 540. I can gem for more avoidance or more stamina I suppose. I don't have multiple gear sets yet ( hit 80 about 2 or 3 weeks ago ) - so I have yet to build up some backup pieces for avoidance/EH/threat - just been trying to keep everything generally balanced.
As a fellow Warrior tank, my advice for you is to drop the expertise gems. Yeah, they're great, but in place of that you could stack Dodge/stam gems or def/stam stuff. I have one hit rating gem, and the rest is Def/Stam/Str, or a combination of them. Otherwise I find that your gear is pretty good for only a few weeks work.