You should get Landsoul's spreadsheet. It'll let you plug in different gear and see a hypothetical raid-buffed DPS. It also lets you pull in from your armory, so you don't have to do the initial setup by hand.
When I look at your character on the spreadsheet, it shows a raid-buffed DPS of 6487. (Note this is theory crafted and based on a predetermined set of buffs you may or may not have all of.)
The first two obvious problems I can see are 1) you're way over-capped on Hit. That's wasted itemization points that could go to better DPS stats, and 2) you've got an EXP/STA gem in your chest.
Second one first:
First, let's go for the socket bonus using the existing EXP/STA Gem, so it's: EXP/STA, EXP, STR/CRIT for yellow. That bumps you to 6500 DPS.
Let's ditch the EXP/STA, and go with a +10 ALL stats there, EXP, and STR/CRIT: That bumps you to 6525 DPS.
All STR would get you 6510 DPS.
So, best to go for the socket bonus there.
I'm not going to go over the rest of your gemming, but I'll point out that the spreadsheet is great to find out if you're better off, say, nudging your Expertise closer to cap or just adding more STR/CRIT.
Also, if you get a DPS socket bonus, it's usually better to socket your yellows for STR/CRIT, provided you don't have to use any DPS loss gems like */STA ones. Just get the spreadsheet and plug 'em in.
Ok, now that we have a baseline of 6525 from going with the +10 ALL, +10 STR/ +10 CRIT, and +20 EXP in the chest, let's look at trinkets:
Replacing the two +Hit trinkets with two that are relatively easy to get, the Needle-encrusted Scorpion and Banner of Victory bumps you up to 6801 DPS. This will leave you at 162 Hit rating, which is fine since you're a space goat. =)
Other combos using non-raid trinkets:
NEC + Darkmoon Card: Greatness: 6858 DPS
Banner of Victory + DMC: G: 6717 DPS
Anyway, hope this helps. You could probably tweak around your gems a bit more, and try to bring up your Crit a little, but overall you're not too bad off. Just hit some heroics for trinkets and regem the chest. Also, again, note that the "DPS" figures I'm throwing out aren't going to actually reflect in game necessarily, but on the level of higher number being better, the spreadsheet is very good at figuring out gear.
EDIT: Oh, one more thing. Make sure you're not getting rage starved. I've started using IceHUD, which is one of the addons that shows you your rage and health bars on either side of your character. It's nice to have that visual indicator where it's easier to see. Also, GupSlamAlert or Power Auras is very handy for not missing slams.
EDIT 2: Looking more closely at your gemming, you're probably missing out on some socket bonuses there. Do your JC gems count as all colors to activate socket bonuses? If so, take advantage of that.