Here's a good idea from the forums: more sheep choices! Polymorph was one of the most beloved spells in the Warcraft RTS games, and so players were thrilled to see it come to World of Warcraft, and even more thrilled when two other variations on the spell were learned: instead of sheeping, players can either polymorph pig or turtle with two learned spells from quests or drops in the game.
But since the introduction of Zul'Gurub, we haven't seen any other options for mages in game. And there are plenty to choose from by now-- Polymorph: Ravager, Polymorph: Clefthoof, or Polymorph: Elekk would all work great. Polymorph: Willy would even be lots of fun. Oh, and yes, as players in the thread say, since we're headed to Northrend, Polymorph: Penguin would not be out of order in the next expansion.
Blizzard has done a pretty good job of taking mounts, both flying and ground-based, towards a little horizontal progress-- giving more options on one level instead of setting up a few options over multiple levels. But hopefully Polymorph will get a little love, too-- even though mages are the only ones who benefit directly, my guild has always had fun making sure our mages have all the Polymorph options possible.