Ok, since cases for the 6G iPod Classics don't seem to exist yet (more specifically, iSkins), I've found that the neoprene case that came with my 5G 60GB iPod fits both of my 80GB and 160GB iPod Classics nicely.. and yes, I bought one of each.

Check the attached photo from the iLounge review.

Any help on eBay or such?

Neither Best Buy or the Apple Store near me carry 6G cases yet. In any case (no pun intended), I've been pretty loyal to iSkin and can't wait to see what they come up with for the Classics. The eVo3 was amazing on my 5G.