Microsoft's vision for the future of computing is currently called Software + Services (or S+S). While S+S is a powerful concept, you won't necessarily "get it" from the name alone, since "software" is a very general term and "services" is an overloaded term which suggests different meanings to different people.
The basic idea is this: whether you're a consumer or a business, you're used to running software locally--that's the "Software" part of S+S, local software you run on your home computer or on your business premesis. In the near future, your options are going to open up. Some of the sofware you run might be "out there in the cloud". That's the "Services" part of S+S--software hosted remotely.
That might not sound like anything terribly new--we've all been "running software hosted remotely" for 10 years whenever we access the World Wide Web--but the capabilities we're going to get as we enter this new era of cloud computing will be new and compelling.
You can read about S+S on MSDN. We'll have lot more detailed information to chew on after the upcoming MS Professional Developer Conference (PDC) where Microsoft will unveil its cloud computing platform.