Will our Fangs of the Father still be awesome? In the 5.0.4 patch, your legendary daggers will be as good or better than they are today. The proc rates have been adjusted for the various specs, and I saw far more procs on the beta than I ever saw on live. Mechanically, they still work out quite well for all three specs. If you were lucky enough to score your orange daggers before Mists, then you can continue using them throughout our time left in Cataclysm.
What about slow off-hand weapons for combat? Since all of the poison and spec changes are active, combat rogues can actually use a slow off-hand weapon without losing much DPS. If you have an extra No'Kaled sitting around and no quick dagger off-hand at that level, feel free to sport two No'Kaleds at once. In fact, double heroic No'Kaled might even be able to compete with the Fangs of the Father. I fully intend to test that theory as soon as I score two heroic No'Kaleds to test with.
Considering that Dragon Soul is already nerfed by 30%, you might as well take this opportunity to try two slow weapons anyway. There's no better time than the inter-expansion gap to try out new things.
Should I use Wound Poison or Deadly Poison? The answer is that you should always use Deadly Poison. Wound Poison is really only valuable in a PvP situation where you are trying to win a battle of attrition. Deadly Poison is going to yield far greater damage in a much shorter period of time. The new single-stack Deadly Poison is effective almost immediately and yields massive damage. I don't think Wound Poison will find its way onto our weapons outside of the arena or rated battlegrounds.
What do I do without a throwing weapon? Don't fret. Rogues will still be able to use our Throw attack without actually having a throwing weapon equipped. Fan of Knives has been redesigned to work off of our melee weapons again, and you can always pick up Deadly Throw if you really want to be able to toss a dagger at someone. Rogues have never been a ranged-heavy class, but we'll still have Throw at our disposal for the off chance that we'll need it to break a CC effect or to aggro a mob.
What should I do with my old poisons? Personally, I save all of my old collector's items. I have Vanishing Powder and Blinding Powder from the days of yore. Our poison items won't actually work, although I will still want to keep them as a memento. I also carry around a stack of hunter arrows, just in case I need to remind them who's in charge. Poisons were one of the few class consumables left in the game. Back in the day, almost every class had consumables it had to track and stock.
How do I get Swirly Ball? You bought all of your glyphs, right? If so, just equip your Glyph of Detection and use your new Detection ability to swirl that ball. If you don't already have that minor glyph, good luck dealing with the auction house. Prices on glyphs have skyrocketed since the patch, but I think we all agree that swirly ball is worth any cost!
What rogue specs are good? The short answer: all of them. The long answer: all of them. Each of the rogue specs should be fine for whatever you want to use them for. I would suggest trying out your least-played spec and taking it for a test drive. Subtlety's rotation has been cleaned up and streamlined, combat rogues are seeing some variety and decision-making, and assassination rogues have our very first proc effect.
What should I be reforging to? First, aim for the 7.5% hit cap and the 7.5% expertise cap, regardless of your spec. After that, I would prioritize haste, then mastery, and then crit. Haste is still an amazing stat for rogues and will help to make sure your rotations feel fast. Mastery and crit might be a toss-up depending on the spec, but chances are that mastery will be fine. If math comes out that proves this wrong, it's nothing that a quick trip to the reforging vendor can't fix.
It's important to realize that there's not a lot of work going into optimizing our level 85 patch 5.0.4 performance. Most rogues are concerned with level 90 and Mists of Pandaria, since the PvP seasons are over and Dragon Soul has been on farm for a long time. As long as you can pull your own weight, focus on Mists of Pandaria rather than obsessing about a few DPS points now.
Sneak in every Wednesday for our Molten Front ganking guide, a deep-dive into the world of playing a subtlety rogue -- and of course, all the basics in our guide to the latest rogue gear.