If I'm interpreting the comments from Bob Nusbaum correctly, then Cisco has decided to stop using the term "DCE" (Data Center Ethernet), and will use the terms "CEE" or "DCB" going forward.
That's a good move. As they are generally used, DCE, CEE, and DCB all refer essentially to the same stuff. Our acroynm-translation lists will get a little shorter, and there will be fewer arguments about the technical distinctions between them.
DCB (Data Center Bridging) has the most well-defined meaning. It represents a set of standards that an IEEE task group is developing that, among other things, helps govern multiple traffic types running over an 802 network.
CEE (Converged Enhanced Ethernet), most famous for being part of the recipe that allows FCoE, refers to DCB done over Ethernet. The term CEE was once trademarked by IBM (but no longer is).
DCE (Data Center Ethernet) was Cisco's trademarked term for CEE. Bob Nusbaum (of Cisco) says the term was causing confusion.