Fixed formatting. Please use preview, you need three brackets, not two, to embed code.
This was answered on the mailing list as a problem with your expectations, not a bug in the code: http://groups.google.com/group/django-users/browse_thread/thread/97885473cb5b4ffd/ so I am not sure why you opened a ticket on it. If you disagree it would have been better to continue the conversation on the list. You have provided no new information/support for your viewpoint in this ticket so the answer here is the same.
Re-displaying a form after successfully processing it is not an expected pattern, nor is it good design from a usability standpoint. Doing work to fix up the form data to reflect a delete is thus a waste of time for the normal case and enabling bad design. I don't believe we should do this.