As a PvP Player, I totally love the new Battlegrounds!
I like the ambiance of the different areas in MoP, along with the very in depth quest lines.
The beautiful terrains!
Pet battles are fun.
really like the non-daily quest, the story line, and scenarios.
Resto Druids not sucking in PvP :]
Green Fire.. Where is it!
I love the raids so far! :)
My favoirte part of mists is the lore. It seems like they have stepped up one thousand fold to get us deep in the story.
Love the raids, the pet battles and oddly enough, I really like the lore behind the Klaxxi
Adding queues at 90 for WG and TB.
I really enjoy the new raid boss mechanics. They are so varied and original.
The pet battles! Can't get enough of them for sure!
Doing the Lorewalkers achiev and learning new stuff about all the pandarians/saurok/etc
Enjoying some lore aspects, I looked forward to Chen's storyline. Other tidbits include: New 'class' mechanics, and not necessarily the pet battles themselves, but the fact that my Netherwing Whelpling isn't sitting in so much dust anymore.
My favorite part of Mists of Pandaria so far is Raid Finder. Most of the fights actually require at least a basic understanding of the strategy for normal and heroic, unlike most of the Cataclysm raid finder, where you could just zerg it and win.
My favorite part of MoP has to be the landscapes and architecture of all the areas in the continent. They really outdid themselves.
All of the Eastern cultural elements. I love me some Asians. :D
+1 to AMD Processor , NICE
Scenarios.