Upgrading Using SVN (Subversion)

I’ve got roughly a dozen blogs I just set up to upgrade using SVN. The instructions for doing so, are excellent.

However, those instructions are all for blog installations that are not at the public_html root so, for that one on my domain, I am a bit nervous about using SVN.

I think the process for moving toward SVN on this blog should be:

1. Delete all the core WP files in my current installation.
2. Leave wp-config.php and .htaccess in place.
4. Leave all other non-WordPress files and folders in place.
3. Do a backup of wp-content.
4. Checkout WP 2.8 from the WordPress SVN server.
5. Restore my original wp-content folder.

If I follow the above, will future upgrades of this blog using SVN leave wp-content and all non-WordPress files and folders untouched?

Thanks in advance!