Once you have submitted the words they become part of the thread and not purely your own. However it might be good to allow them to be anonymised later.
I'd prefer allowing them to become pseudonymous later. I still think it's useful to be able to take a comment in context of other things that individual/account has said.
Of course, I guess this could be easily done if you could change your userid (on the backend, it's proabably a GUID or sequence number anyway).
