I'm a consultant and I would love to see Ubuntu supported on Symantec ITMS. I would think the Long Term Supported (LTS) would be suported and not the various point releases.
have you reached out to Canonical at all about this? I have a lot of good friends at Canonical and wouldn't mind reaching out to them as well if there is interested.
Been working with Ubuntu since it first reelases and there are several connect posts about how to install the agent on ITMS.
Problem from an installation point is the diffference between YUM and APT, right now you guys use YUM for all installations and would probablly require a re-write of things or pull in the various YUM dependencies