Definitely not. If this feature did exist it would make it dead easy for someone to "hi-jack" your account if they managed to login as you (e.g. if you forgot to log out of a public computer or someone knew your password). As they could then change your username to something else without you being aware of the change. If you need to change your username then you should ask me to do it for you and likewise if you want your account to be deleted.