Before anyone asks - yes there are archived copies of old addon versions both on our github repository and on several of the addon sites we use, and these will continue to be available after Cataclysm comes out, so you'll be able to get those old files if you really want them. I'm not going to bother making these more easily accessible unless you give me a very good reason. "I'm on a private server and I need them since we didn't upgrade to Cataclysm" is a BAD reason - and it's illegal.
Also note that power leveling is sometimes used to refer to paying someone else to level your character to cap as fast as possible (i.e. they power level for you); a distinction used by Blizzard is to refer to the paid leveling as "power leveling service." This behavior is against Blizzard's Terms of Service. Power leveling yourself, which this article covers, is perfectly acceptable.
If you already have a high-level character and want to quickly level up a new one, by far the best tools for the job are the items labeled “heirloom gear.” These pieces of gear have two very special properties — they bind to your account, so any character you own can use them, and they grant bonus experience. Their stats also scale with your character’s level up to a certain point, so you can equip a fresh character with heirloom gear and power through much of the game.
Même logique que du côté de la Horde, Drustvar est la zone la plus difficile, et la Vallée Chantorage la plus facile lorsque les choses se corsent. Nous vous recommandons également d'attendre le niveau 120 avant de lancer la Campagne de Guerre, puisque celle-ci va juste vous faire sortir du sentier. Nous vous conseillons également de ne pas tuer de monstres rares ou de récupérer de trésors, puisqu'ils ne sont pas si rentables que ça. L'équipement trouvé sur les monstres rare est en plus meilleur à plus haut niveau grâce au scaling : une raison de plus pour attendre d'être niveau 120 avant de les tuer !
Certain locations in World of Warcraft – primarily inns, capital cities, and private instanced zones like your garrison or class order hall – are rest areas. You know you’ve entered one because your character portrait will gain a “Zzz” icon where your level is normally shown, and because you can immediately log out of the game instead of waiting 20 seconds.
Special note: At 110 it's almost certainly worthwhile to go and immediately get your Heart of Azeroth and first piece of Azerite gear from the BfA opening quest. It doesn't take long and provides pretty high power levels. I'd then return to Legion quests until 111 or even 112, since the power of these items will increase your kill speed significantly over the scaled enemies of BfA content.
Heirlooms are special pieces of armor that level up with your character, so they have stats that are always respectable for your character’s level (up to level 110). Heirlooms that fit the head, shoulder, chest, legs, and back armor slot offer an experience bonus. The total bonus is 45 percent if you have them all. It’s also possible to acquire a ring that adds another 5 percent, but you must win a fishing contest acquire it, and that can take some time.