There are more options than just Alabanza and VDI's CP. Plesk & Webmin and other forms of wannabe's. Check out this link
http://www.psoft.net/ and do a test drive of H-Sphere. A new release is coming out in 2 months time that will also include a mailing list facility. There are other developments going in terms of "ControlPanel" for UNIX/Linux server

And also... Cobalt Networks is not the only company in this market, altough first out a few years back there are others that are planning to do the same based on a higher spec 1U machine with it's own CP. Cobalt in it's third generation still lack alot and if they don't do anyhting about that others will catch up

Great things are coming...