Don't worry - I'll quit WoW as soon as I can get my paws on Starcraft II.
It's kind of like reading a Robert Kiyosaki book - getting to the end and needing to buy the next book right away. The content makes you feel good but it always leaves you feeling a bit undernourished, hoping the next fix will finally complete you - leaving you whole.
The preceding was a bit of self-reflection, perhaps. :)