So I managed to finish off my shaman last week, getting them to 90 right about on average at 21 hours. So I've now started leveling my new Pandaren Monk and have managed to get him to level 44 in just a couple of days. The experience boosts that come with the Monk class are a huge help. Probably doesn't hurt that I have him completed kitted out in heirloom gear as well. So if I'm doing the math right, he's getting a 50% xp boost from the monk dailies, a 25% boost from guild perks and a 50% boost from heirloom gear. So we're flying through stuff at this point.
I also managed to finish archeology on my warlock. The changes to that profession now with 5.1 have made that a lot easier. It took just an hour or two to go from 485 to 600.
I'm still working on getting the Spear of Xuen for my monk. I've done about 7 pandaren artifacts so far and no luck yet, but I'm going to keep at it.
My plan is to try to get the Monk to 90 before 5.2 drops, but we'll see if that's really possible.