Regardless of your spec of choice, leveling your rogue in Mists of Pandaria should be an enjoyable experience. I tend to enjoy combat's simple Sinister Strike-spamming playstyle for the leveling grind, but subtlety's amazing burst and assassination's potent poisons are more than powerful enough to get the job done. If you were lucky enough to acquire your Fangs of the Father, they'll carry you until level 88 or 89 with their awesome damage.
The first key to a swift leveling experience is to minimize your downtime. The less time you spend in combat, the longer it will take to hit 90. The second key is to increase your damage output. While our damage is already formidable, taking out targets faster is always a good thing. The third and final key is to eliminate the competition. If a member of the opposing faction is killing mobs in the same area that you are, you need to increase the supply of mobs by reducing the demand.
Building a zero-downtime rogue
I heralded Recuperate's anti-downtime capabilities in Cataclysm, but there's a new form of rogue healing in town. Leeching Poison is incredibly potent. You can mow down mobs and end each fight with full health. There's also some great synergy with the Glyph of Blade Flurry for combat, as the extra Leeching Poison hits allow you to easily tank a second mob. Cheat Death and Elusiveness are both weak options for leveling, so Leeching Poison will be a crucial piece to everyone's leveling build.
While the Glyph of Stealth might not look amazing, it's actually a great leveling glyph. It allows you to enter Stealth more rapidly between kills. With great Stealth/opener talents like Shadow Focus, there's really no reason not to open on every mob you approach. Even combat rogues can get in on the opening action. The Glyph of Evasion is another glyph option that can reduce your downtime by making you like a tank. I wouldn't bother with the Glyph of Recuperate, simply because Leeching Poison will handle all of your healing needs.
Never stop attacking
Assassination rogues used to have exclusive access to Deadly Momentum, but it was wisely transformed into a major glyph. The Glyph of Deadly Momentum allows you to maintain your Slice and Dice (and Recuperate) buff while moving between enemies. Because you're trying to kill as many mobs as quickly as possible, having Slice and Dice up at all times without spending any combo points on it is great. You can save your combo points for powerful Eviscerates and Envenoms while keeping the powerful haste bonus.
While our Prey on the Weak talent won't see much use in raids, it does provide combat rogues with an interesting opening option. While assassination and subtlety rogues will probably be opening with Ambush, Prey on the Weak can make Cheap Shot a viable opener. When combined with the Glyph of Cheap Shot to extend CS' duration, you can get quite a bit of bonus damage in. I could even see subtlety or assassination rogues using Sap first and then Ambushing their targets for the free 10% damage boost. Because Shadow Focus reduces Sap's energy cost to zero, your only cost is a global cooldown.
Edging out your opponents
One of Mists' best-kept secrets is PvP power, the new PvP-oriented stat. While PvP power does nothing in instances or raids, it increase your damage done in the open world and while questing. You can toss on your PvP gear and still deal great damage to normal mobs and other players. I will be using my PvP trinkets and a few pieces of my PvP armor to boost my defenses against enemies and to also give myself an edge when I'm going in for a gank.
If you find a member of the opposing faction taking your nodes or mobs, you need to eliminate them. Combat rogues can unleash a Cheap Shot and Killing Spree combo, while subtlety rogues can drop a few Ambushes into their spines. Assassination rogues can be very effective applying bleeds to their target, waiting for energy, and then spamming Mutilate and Envenom for quick bursts of damage. If you're playing on a PvP server, then you know that launch events are PvP hotbeds. You need to expect to be attacked and you will be forced to defend your turf more than once while leveling.
Maintain your core stats
Hit and expertise are far and away the two best leveling stats you can get your hands on. I would try to reforge every time you move up a level to ensure that you're at the hit and expertise caps at all times. You can even pile on some extra expertise since you'll be attacking mobs from the front quite often, and more expertise can help to negate some of their parry chance. By the time you hit level 90, all of your gear will need to be reforged into hit and expertise to even get close to the caps. Don't worry about haste or mastery or crit, as hit and expertise are simply too good while leveling.
You can also burn through your Skewered Eel and Flasks of the Winds to boost your agility while leveling. Prices on these consumables should hit the floor as Mists launches and they're made obsolete. I am also going to have a few basic Cataclysm gems cut and ready to socket into my new level 85+ gear since all of the new gems are going to cost way too much money. Don't worry about enchanting anything, just reforge your gear every level and you'll be fine.
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.