Microsoft irrevocably promises not to assert any Microsoft Necessary Claims against you for making, using, selling, offering for sale, importing or distributing any implementation, to the extent it conforms to one of the Covered Specifications, and is compliant with all of the required parts of the mandatory provisions of that specification
Basically, it says that developers soon will be able to implement their own versions of C# and CLI, as long as those will abide Microsoft's technology specifications.
Scott Guthrie mentioned recently that:
Scott Guthrie said:
The Community Promise is an excellent vehicle and, in this situation, ensures the best balance of interoperability and flexibility for developers.
The time will show, but I guess we will soon see a more solid support for C# and CLI on various platforms.