WordPress MU

I would like to use MU for sites on multiple domains and multiple sql servers (all through one shared GoDaddy hosting account).

Is there a relatively simple way to switch them to MU, keep all of my plugins/themes from all of my sites, they are basically the same set of plugins with a few differences.

All of my sites get a light load of traffic to my shared hosting server, 20-30 people per day, per site, for four different WP 3.0 installs. Unfortunately, I don't have a lot of comments, so a few minutes to a couple hours of downtime wouldn't hurt my sites.

Pick which one you want to be the main site.
Enable the network.
http://codex.wordpress.org/Create_A_Network

Make new sites in either subdomain or subfolders. Won't matter.
Export the stuff out of your existing sites into the new sites.
Map the domains.
http://wordpress.org/extend/plugins/wordpress-mu-domain-mapping/