I noticed a comment thread on Groklaw about Moonlight, with a link to the license terms on Microsoft's website. They call it Covenant to Downstream Recipients of Moonlight - Microsoft & Novell Interoperability Collaboration . A comment by Microsoft's Brian Goldfarb on Dana Blankenhorn's article about Novell being a lead pony for Silverlight started the discussion originally.

Here is what seems like new attempt s to justify the use of Mono at Java's expense

We have received some mail recently from developers who are concerned about issues that are covered here, including OOXML and Mono. One person, for example, was concerned about pressure on KDE to implement support for OOXML (a big no-no). Coming from Debian, a concerned developer spoke about the problems surrounding Mono. Together, we ought to at least try to inform.

There has been a wide range of discussion on the subject of Mono and its inclusion in Ubuntu by default. Some people believe that Mono may infringe on Microsoft patents while others believe that it is useful to include. Personally, I have no idea about whether Mono does infringe on Microsoft patents, but I see other reasons why Ubuntu should remove it.