The FOSS community has been concerned about the difficulties, pros and cons of including Mono-built applications as a part of standard Linux builds. Both Pro and Con.
Most recently, the Ubuntu Technical Board posted to their Ubuntu Developer Announce mailing list their extermely pragmatic position on Mono applications.
Today Microsoft extended the Community Promise to the two underlying ECMA (and subsequent ISO) standards that cover the CLI and C#. These promises had already covered other EMCA standards such as OpenXML, so it was quite logical that the CLI and C# would follow. Well, in a sane universe anyway.
As the Mono project (and Moonlight) are based on these standards, the Community Promise would logically extend to these environments.
Hopefully now we can all just build cool software, not argue about licenses, patents and other distractions. Now let's fix Outlook's HTML rendering!. :-)