Blizz stated in a watercooler that they're using the 1.12 database as a starting point. I don't think it's a stretch for people to assume that most game features and mechanics will be in their 1.12 state. The kind of stuff I would expect to see reverted would be numerous AV changes, but I seriously doubt class mechanics are going to be reverted. I'd be surprised if the threat changes that ruin pre-naxx encounters are reverted.
When it comes to levelling the Priest Class from 1-60 fast, XP grinding locations is only half the battle. You will need to make sure your weapon does enough DPS so that you can clear these mobs fast enough, it should also be noted that monster should be around your level to make sure to gain the 100% XP Reward. The Level your character should be before you start that specific location will be indicated to left in a Blue Color for Alliance [Lvl 35-39] and the Orange Color for Horde [Lvl 35-39]. The Mobs you are looking for in that specific area names are Bolded [Mob Name].
ConsolePort: A WoW addon which natively supports Xbox and DualShock controllers. WoWMapper: Third-party software for keyboard and mouse emulation. This software is not against the ToS, because it does not automate your gameplay. Multiboxers are without any issues using ISBoxer for instance. Xbox or a DualShock controller: Alternatively, you can use a Steam controller and enable Stream streaming. Setup instructions can be found here. DualShock's touchpad acts like a mouse, which is quite nice. A long HDMI cable: In case you decide to hook up your PC to a TV. Instructions