Yes they do. They provide both English and German titles. But players use the English ones.
Look, even each patch gets translated: http://eu.battle.net/wow/de/game/patch-notes/6-2 (current patch: "Zorn des Höllenfeuers")
And here, the thunderking (Der Donnerkönig) patch video in German
I don't want to derail this into a German thread, I'll just say that every inch of content gets translated, even though players still use the English titles.
We are the Knights who say OF!
Originally Posted by Blizzard Entertainment
It could be worse:
Red and Blue
Gold and Silver
Diamond and Pearl
Heartgold and Soulsilver
FireRed and LeafGreen
Ruby and Sapphire
X and Y
Just sayin'. LOL.