Old usernames and names of deleted users in CW-mode
See this answer for reference: Advantages of IMO students in Mathematical Research
Note that the last edit shows up as "Bill Dubuque." However, this is an old username. If you click on the edit history, his username shows up as "Gone," as it should (now). I don't know if this is a known bug or not, but thought I should report it.
In short: If you edit a community wiki and then change your username, it still shows up as the old username on the main question page for the wiki. However, if you click the edit history for the wiki, it shows the new username.