I have caught-up the discussion on the topic of the short description now. (I was not subscribed to debian-policy so I didn't follow the discussion itself.) As the original bug-submitter I want to make some final comments:
* I agree with most of Branden's proposal since it grants consistency in package description. Consistency is important IMO, since the current differences in package descriptions can easily make the impression of "unprofessionalism". * I do also agree with the people that said that this doesn't belong into policy. The Developer's Reference is probably a better place for it. * As for the original discussion, whether we should mandate capitalization/punctuation: The points that were made against this were good IMO and I agree that lower case and no full stop should be the "default". - Sebastian