I find myself wondering what else they could really do with the Classic. WiFi won't really work with the click wheel, which I think is at the essence of the classic. Click wheels have been gradually disappearing from the Apple line up as a whole, so I'm guessing that it's going to be discontinued soon.
They could add more colours, but would people buy it? It'd look too much like the 3rd gen nano too. In my opinion they need more features than just the lightning connector to get people to buy it. I don't see the memory options needing to go any higher on the Classic either.