I still have a folder called "System Folder" that belongs to the Classic environment. It takes up almost 400MB on my disk. Since I'm running Lion, can I safely delete the entire folder?
I did a clean install of Lion and there is no "/System Folder/" there, therefore I believe that you can safely delete the folder "/System Folder/" however make sure you do not delete the "/System/" folder, otherwise you'll be left with an unbootable system.
(Of course you have a working backup, right ;-?)