Mists of Panderia is just what WoW was needing. Let me explain.
For the past three expansions, we've all been focused on taking some big endboss baddy, a "main villain" of each expansion. This has gotten old, because it makes each expansion resemble each other too much; it makes each expansion more or less the same story wrapped in a different skin. We arrive at <insert new land here>, work our way through <new lands and dungeons here> en route to main boss, and kill the main boss. Next expansion arrives and we rinse and repeat.
In contrast, Mists of Panderia looks to be set up more like the original WoW. Vanilla WoW had no primary boss; the main enemy to the Horde and Alliance were each other, which gave Blizzard massive liberties when it came to crafting each zone, dungeon, raid, and even battleground. It meant that they were not bound to a single theme that matched the expansion, and allowed them to create a staggering variety of zones, dungeons, raids, and battlegrounds each with their own distinct look and feel. Even the original tier gear was more varied in theme because of this.
This is largely what contributed to WoW's original success, and it can only be good for the game if they manage to bring it back.