This reproduces with r15650 of trunk (HEAD right now):
$ svn info
Path: .
URL: http://svn.collab.net/repos/cvs2svn/trunk
Repository Root: http://svn.collab.net/repos/cvs2svn
Repository UUID: be7e6eca-30d4-0310-a8e5-ac0d63af7087
Revision: 1428
Node Kind: directory
Schedule: normal
Last Changed Author: fitz
Last Changed Rev: 1428
Last Changed Date: 2005-05-23 11:01:32 -0500 (Mon, 23 May 2005)
Properties Last Updated: 2004-07-07 10:22:36 -0500 (Wed, 07 Jul 2004)
$ svn switch --relocate http://svn.collab.net/repos/cvs2svn/trunk \
http://cvs2svn.tigris.org/svn/cvs2svn/trunk .
$ svn info
Path: .
URL: http://svn.collab.net/repos/cvs2svn/trunk
Repository Root: http://svn.collab.net/repos/cvs2svn
Repository UUID: be7e6eca-30d4-0310-a8e5-ac0d63af7087
Revision: 1428
Node Kind: directory
Schedule: normal
Last Changed Author: fitz
Last Changed Rev: 1428
Last Changed Date: 2005-05-23 11:01:32 -0500 (Mon, 23 May 2005)
Properties Last Updated: 2004-07-07 10:22:36 -0500 (Wed, 07 Jul 2004)
$
Notice how the URL hasn't changed, even though 'switch --relocate' didn't error.