The crafting process for the Sulfuron Hammer is the grindiest part of this process, as it requires a large amount of difficult to obtain mats, but the Eye itself also has a low (2%-ish) drop chance off Ragnaros, so both parts will require a whole lot of time. This creates a bit of a conundrum, as the logical thing to do is wait until/if you manage to get the Eye for yourself and then start the grind for the crafted hammer. However, unless you get really lucky and get the Eye to drop very early in your Molten Core clears, this is a little impractical as it will take you a long time to gather up all the mats needed, and if you really have your heart set on Sulfuras, you might want to start before you get the Eye. This, of course, is further complicated by some of the mats being drops off bosses in Molten Core, meaning they're either guild property or you'll have to roll for them in pugs. The easy answer here, obviously, is having a good guild that will either decide who's getting the hammer ahead of time, or will bank all the mats and have them ready for whoever gets the Eye when it drops. This also isn't as easy as it sounds, as the big pain-in-the-*filtered* mat required here involves a whole lot of alchemist 2-day cooldown transmutes, which again requires a whole lot of planning.
While you get Cat Form at 20, there will be many instances in this level bracket where it’s preferable to sit in Bear Form. One reason is that you don’t have an efficient finisher for your combo points in Cat Form at this stage and you don’t even get Shred until 22. Secondly, you are penalized more swapping from Caster to Cat than from Caster to Bear as you start with potentially 0 energy, since Furor won’t be 5/5 till 27.

The Horde levels 50-60 guide has been rewritten and revamped.  My 1-60 Horde leveling guide is now completely updated for the 1.12 Drums of War patch.  As you can see it is about 15% larger than the 40-50 guide (single largest guide page yet).  There is also a lot of route changes.  I moved the entire Silithus section from level 55 to level 58, which allowed me to include a lot more quests for that zone.  There is also a lot of other improvement to the route, including adding a lot more quests into the guide, mostly from Moonglade, Silithus and Eastern Plaguelands.  This will make the final level 59 grind much shorter.
While this build isn’t too different from the dungeon build, it definitely works better in a raid environment. Threat and range are less of an issue in a raid, so a shadow priest benefits from 5 points in Mental Agility in the discipline tree to help lower mana costs. You also won’t use Vampiric Embrace in a raid, as it typically does more harm than good for you. You’ll still have access to Inner Focus, which grants a mana-free Mind Blast with a great chance to crit.
On top of that, you’ll also need a “rotation” to keep up with mana regeneration. You’ll generally want to use a Major Mana Potion after you’ve used enough mana to fully benefit from one. If you have enough health and raid damage is low, you can also use a Demonic Rune. If both of those are on cooldown, you’ll want to stop using Mind Blast in your rotation, and instead just cast Mind Flay when you have enough mana to keep Shadow Weaving applied. If you’re really lucky, a druid might Innervate you (don’t count on it).
That was the only 5 minutes I was ever outside of Nihilum since I joined it, and to be completely honest with you, I can't even remember what happened with that god damned belt. I think I ended up taking it either for free or for a highly discounted price, but it's the drama that stuck with me and not the actual DKP or belt. And in closing, as you might expect, I didn't ever get the Sulfuras or the Eye, as it simply didn't drop while I was ahead on points. I did, however, grind a whole lot of Rich Thorium Veins in preparation for both it and Thunderfury, for which I actually had the left binding - and also never got. 

Picking the best race for the priest is difficult since this class gets unique spells based on its race, these affect how we rank the best drastically. For Horde for sure if you are going shadow you will want Undead, and Alliance can choose between Humans and Dwarves. With PVP in mind, we think Dwarves have an edge of humans, but they are both good choices so either will work.
Aux delivers a more advanced UI for the auction house. At times you want to buy a lot of materials and you want to buy for the lowest price possible. Aux let you list an item ordered by the price per item. Another neat function is that Aux can post multiple stack for you on the auction house. If you use the default action UI you have to post each stack manually.