It's not a copyright issue, but a patent issue. Patents are related to ideas, while copyright to physical implementations. Having said this, I wouldn't worry about it too much. Microsoft is really just covering it's ass here, preventing someone else from patenting the idea and then forcing THEM to license it. I doubt highly that MS would come after anyone for patent licensing (they've never done so, except when they've been sued first, such as with Stac). But it's up to you.