Performed the upgrade without problems, but one of the reasons to do the upgrade was to enable multi-site support.
I've performed the initial edit of /wp-config.php as directed in http://codex.wordpress.org/Create_A_Network ... Step 3, but the
Network Tool isn't popping in the Tools menu.
Everything else seems to be working, but because the Network tools aren't available, we can't go multi-site.