I wouldn't put preventing an occasional (deliberatly?) confusing username very high on my priority list. The amount of new users that will be unfairly restricted in their choice of name will probably be much higher.

I would think it's possible for the gods to change someone's username if it turns out to be too confusing. If people really try to abuse the system - and they can anyway, restrictions or not - the most appropriate action would be to disable their account, but I haven't seen any reason to do that (but I must admit I wasn't really paying attention this morning).

Joost.