How can I show the Cover Art window in iTunes 11? I like to see the album art for each song as it comes on; in iTunes 10, I would have iTunes DJ playing, hidden under my other apps, whilst the current song's cover displayed in a floating window on my second monitor...

Can I do something similar in iTunes 11? (at the moment, I'm using the iTunes DJ replacement suggested here, but the thumbnail is tiny!)

I've sifted through the menu and prefs, but didn't find anything.. I'm hoping that someone will have a tricky way / script that replaces my 2nd Desktop Wallpaper with the art!?

Fingers crossed, Tx!
To get the second window back, all you have to do is click the album artwork thumbnail in the Now Playing area, either in the full version:



Or in the Mini Player



Both will pop up the larger album art view you are looking for. 

In iTunes 11.0, there currently isn't the sidebar album art view that used to be there.