Those servers are central to validate the “Microsoft Genuine Advantage” service. In plain words, they provide the verification that you are really a registered user authorized by Microsoft. But these servers are currently down (some kind of network failure?) and Microsoft forecast about two days before going back to a normal situation. This simply means plenty of problems for the clients willing to authentify themselves, either because they just installed a Microsoft software, or because they upgrade one.
This is a new example of why I am against copy protection and DRM. Pirates will obviously not notice the event and won’t even be annoyed. But legal customers of Microsoft are stuck waiting for the repair of these servers in order to come back to normal use of their software. Clearly, copy protection is not a customer service, only a mean to a sales end.