I think that graphically the cartoony and even slightly candy coloured style of World of Warcraft is quite fitting for the title. Sometimes it can be too flashy and the game is starting to show its age but I don't think that notably more realistic graphics such as those offered by many other games would suit it too as well.
If I was to improve something, it would be to make darkness a more notable element in the game. There is not a single place in the game world that is actually
dark, except perhaps the Emerald Dragonshrine in End Time. This is a factor that I believe would hugely enhance my in-game experience and could be used to make areas such are Icecrown tad bit more threatening.
Some examples of how darkness might look like in World of Warcraft:
http://imgur.com/a/XH1gS
I'm also including few resized examples below.
Mage Tower
Random Lamppost
