As you already realize, Wikia has rolled out a new skin to all their wikis.
The "Monaco" skin that you were all used to has been removed by wikia.
You now have two options: MonoBook or the New Wikia look.
To switch between the two, go to your user preferences, scroll down to the 'Site Layouts' section and click the radio button to select your preferred option.
Certain advanced editing-features are only available on the New Wikia look.
Forum:New skin has been set up if anyone has any questions or spots an issue with the new skin and this site.