MoP Blue Drops are Amazing
Blizzard threw us an interesting curveball this expansion by giving us blue item drops in MoP for the level range of the PREVIOUS expansion with inflated item levels. Namely level 80-85 blue(rare) quality gear. These gear pieces allow for players to twink out a toon like never before and create an amazing opportunity for the opportunistic AH goblin.
Examples like [Bjam's Door-Breaker] show just how crazy an item level you can put on a level 80-85 toon while they are still running Cata content. What is particularly crazy about this gear is a level 85 MoP blue BoE drop has an item level of 450, which is the same ilvl as most crafted lvl 90 BoE blues. An even better example is the lvl 87 epics that drop in MoP. Those items are only ilvl 440. Yup, a lvl 85 MoP blue drop has a better ilvl than a lvl 87 epic. People love this stuff and will pay A LOT of gold for it, I am personally still using a lvl 84 MoP blue trinket at level 90, [Gerp's Perfect Arrow], because I simply haven't found a better one yet.
On top of the 80-85 blues that MoP mobs drops are player-crafted blue proc items. Ghost-forged, Misthide, Stormscale, and Windwool gear crafted by the various gear crafting professions can proc a blue quality piece of gear when crafting the greens. The suffixes are random but I've found that every single suffix and stat combo has value. I've found that in addition to the MoP blue gear drops that it is very profitable to search the AH for these blue procs as players often list them cheap(sometimes just as cheap as the greens) and they can be very easily flipped for quick profits.
There is a VERY LARGE list of MoP blue gear drops in the lvl 80-85 range, so much so that I broke my Auctionator shopping list down into several groupings to filter it into more manageable groups to look through. They are as follows:
Armor/80/84/i409 - This grouping is humongous. So many great pieces of gear to be flipped. Keep an eye out for trinkets like [Grakl's Gleaming Talisman] and [Core of Decency] as the trinkets can be flipped for large amounts of gold with ease.
Armor/85/85/i450 - [Daelo's Final Words] and [Record of Mysterious Deeds] are two of the better items in this grouping for flipping, but all of them can make you huge profits(especially Daelo's).
Armor/Ghost-forged/i415 - This grouping filters only blue quality ghost-forged crafted gear(you avoid the greens by requiring the ilvl be at least 415). It's very easy to resell these blues as players hitting 85 look for cheaper options to bump their ilvl for running dungeons.
Armor/Misthide/i415 - Same deal as ghost-forged gear but this grouping is leather gear so the demand is quite high as tons of new monks level up.
Armor/Stormscale/i415 - Maybe it's just my server but I am getting huge profits for flipping Stormscale blues as the supply seems very limited. I'm especially making huge profits flipping [Stormscale Drape] for as much as 2500g(keep in mind this item is actually a lvl 90 cloak). I've had no issues listing other Stormscale agi items for 650-750g, but ymmv.
Armor/Windwool/i415 - This grouping gets flooded alot(since cloth is so dang plentiful) but the demand is pretty high too so it's still worth flipping this gear.
Weapon/80/84/i409 - [Bjam's Door-Breaker] is the all-star of this grouping. I've sold 6 or 7 of them since I started doing this about 10 days ago and have gotten 2k+ profits on each one. That being said, there are quite a few great weapons and since weapons more than any other piece of gear have the greatest potential on increasing performance people will pay exorbitant amounts for these pieces.
Weapon/85/85/i415 (Updated 11/18/12) - This group is somewhat small but the standout is [Fist of Fate] as players will often buy 2 of them to Dual Wield and as such the supply dries up quick and you can charge a premium. This grouping also includes the i415 Blacksmithing crafted weapons, the [Rain Poppy Staff](made by inscription), as well as the [Fishsticker Crossbow] All of the items in this grouping have great profit potential.
Things to Keep in Mind
*The market value of these MoP blues vary greatly. Some of them have much lower demand than others(like [Light-Sealed Casque]), and some just have ridiculously high supply which drives down market prices. Use theunderminejournal.com to help you judge the value of these items before flipping.
*Weapons and trinkets will often sell for more than other blues. This has pretty much always held true because these pieces of gear have the greatest impact on perfomance.
*Keep an eye out for Helms with meta sockets(like [Davidian's All-Seeing Eyes]). A meta socket is a precious thing and players will pay a great deal for a helm that has one.
*Don't be too afraid to buy several copies of the same item. Test the waters a little. The supply of any particular blue has its ebbs and flows, but eventually the supply dries up a little and you can get a premium for your copies.
*If you get notifications from TUJ, I encourage to consider adding all the MoP blue drop gear items you find. People are frequently posting these things at way under market value and being the first one to find out means you're the one who gets the profits.
*Level 80 MoP blues in particular can have an inflated value because it is the lowest level at which you can twink out with an MoP quality blue.
Some Final Thoughts
The MoP blue market is quite possibly the most exciting market I'm in right now. I see this market being active and profitable for this entire expansion, just like the 77-80 Cata greens were in Cataclysm. Never before has Blizzard basically decided to retroactively add Blue quality gear for a previous expansion's gear level through drops in the new xpac. And I can tell you, I have received more whispers about my item listings from this market than any other market I have ever been in. The demand is there and I believe it will be for a long time.
I hope this was helpful and you achieve great success in this new market. Let us all know about your experiences in this great new market, and if this was helpful to you I would very much appreciate a +rep! May the goldz be with you!