Cover your feet, you'll catch a cold
DPS boots can be hard to acquire before you step into Kara, and since there's only one option for DPS boots in Kara, you'll probably end up getting it sooner or later. Still, if you're interested in covering your feet in some metal designed for kicking, you have a few choices.
The Obsidian Clodstompers are often a popular tanking choice. But as you can see, while certainly suitable when gemmed properly for tanking, they also have a nice 64 attack power from the strength before you count buffs, and with two gem sockets (yellow meaning you can slap green or orange gems in here too) you can customize them for DPS as easily as for tanking. If for some reason the Clodstompers won't drop you can make a similar gem choice with the Sha'tari Wrought Greaves, which won't require you to worry about drop rates as they are a quest reward. If you're running heroic Blood Furnace, Kelidan can drop the Bloodsworn Warboots, which have a nice dose of hit on them but aren't really superior to either of the previous options due to their sockets, giving them great flexibility. (On the other hand, if you have the Bloodsworns then you can gem one of the others for an offtank set.)
If you are doing the Ogri'la dailies anyway you might want to take a look at the Vortex Walking Boots. Decent stats (slightly inferior to the Obsidian Clodstompers), two sockets and a dose of crit rating in addition. While they're certainly serviceable boots, I'd really suggest any serious DPS warrior take a look at the Sunstrider Warboots instead, from Magisters Terrace. Once you have at least 500 armor penetration, it becomes a very nice DPS stat, and these aren't hard to get as they drop on both normal and heroic. Finally, if you want boots that will serve for both offtanking and DPS, there's the Eaglecrest Warboots from heroic Blood Furnace again. Kelidan, in fact. He's got a lot of shoes.
Finally, if you have 40 badges of justice eating a hole in your pocket, you can pick up the Veteran's Plate Greaves on the Isle of Quel'Danas, or you can run battlegrounds and collect honor and 40 eye of the storm markers to get the superior Vindicator's Plate Greaves. Both are solid choices for DPS shoes despite the wasted resilience budget.
Wear a belt or your pants will fall down
Ah, waist armor. So necessary, and yet, so often so hard to find. Well, what are our options here?
Since there's no DPS belt inside Karazhan for you at all, I've decided to talk about badge options that will take you past it. The 60 badge belt from G'eras in Shattrath, the Chain of Unleashed Rage, is a solid DPS belt with hit rating, armor pen, good stats and two sockets. It doesn't have crit, but you can't have everything. Another belt that will take you past Karazhan is the Red Belt of Battle. It's a craftable epic, often found on the AH, and has crit rating instead of armor pen, the same amount of sockets and hit rating, and more base AP. I use the Red Belt myself, but either is suitable. A strong choice for a fury offtank is the Lion's Heart Girdle, which has decent DPS stats as well as defense for tanking.
Talon King Ikiss in Sethekk Halls drops the solid Deathforge Girdle, which visually matches the Doomplate set. I wore it for a very long time on my tauren before I finally got him a Red Belt. If you run Arcatraz a lot you can pick up the Rubidium War Girdle, which is a decent belt, but in terms of raw DPS stats it's barely 2 AP and no crit over the Girdle of Siege, an AH BoE drop you can equip at level 63. They even look the same. (So does Borak's Belt of Bravery, while we're at it. But since you'll probably do the quest to get it anyway, might as well mention it.)
Honestly, unless you have the Red Belt or Chain of Unleashed Rage already, I'd say save the honor and marks and get the new Guardian's Plate Belt. Massive crit rating, solid AP, and no arena rating required. Karazhan has nothing you'd replace any of those three with anyway.
My wrists ache, do you have anything for that?
What does the stylish DPS warrior slap on his wrists to be ready for Karazhan? Well, I don't know. Style's never really been my thing. I just kind of go with whatever I think will hurt people more.
35 Badges will get you the Eternium Rage Shackles. If you're building an armor pen set, these are definitely worth looking at, and 35 badges isn't that hard to acquire (it's effectively one and a half Kara runs, so if you run the daily heroic once a day and Karazhan that week, you can sport these bracers within that week.) If you expect to be doing a lot of offtanking as a DPS warrior there's the Amber Bands of the Aggressor from heroic Steamvaults. If you are a blacksmith, know a blacksmith, or feel like crawling the AH for a few days it's very likely that you can pick up a pair of Black Felsteel Bracers.
If you're looking for things to wear before getting any one of these options, there are still a few choices. Blacksmiths can make the flexible Adamantite Plate Bracers or you can buy a pair on the AH, these can be socketed to serviceable status for whatever you need from them. AH crawling can also provide you with the Bracers of Recklessness while you're leveling to 70. If you're in Sethekk anyway for a belt you might keep your eyes sharp for the Bands of Syth of off, well, Darkweaver Syth. Thankfully the Panties of Syth don't drop. If you want slightly more AP and less everything else and are willing to wear a 64 blue, there's the Nexus-Bracers of Vigor from normal Mana-Tombs. Finally, if you're in normal Magisters' anyway, you can pick up the Bracers of Slaughter, with slightly lower AP than you might expect but a socket and some crit.
Finally, so as to not leave our our PvP option, there's the Vindicator's Plate Bracers. Nearly as much AP and crit and a socket makes them superior to the Black Felsteel for DPS, in my opinion, despite the wasted item budget for resilience and high stamina. (Wasted for PvE, of course, not PvP.)
There are probably a boatload of options I'm forgetting. Perhaps I only think so because this roundup is relatively shorter than previous ones (it's still long, but not as ridiculously long as previous posts). I'm thinking a roundup of the DPS and tanking options for T5, T6 and Sunwell content are all long past due, so I'm leaning towards doing that in the future. For now, I wish you all a good plunge into whatever raid you're raiding next.