That is what I expected to happen one day, despite those people saying "this will never happen".

It is the reason why
autorevision first tries to get the revision from
svn rather than scanning the
entries file.
Subversion 1.4 uses a new format for the working copy. The update is done automatically, you won't even notice it. But once the working copy has been updated, you won't be able to access it with clients linked to older versions of the Subversion library.
So, you should install
svn on your PC, or you'll have to live with it for a couple of days until I update the tool for 1.4.