"The difference between services and software is largely frame of reference. Services are ultimately provided by software and hosted somewhere. Microsoft wants to provide the best solutions for consuming, providing, and combining services, whether they are data or rich media, and whether they live behind the firewall as ws-* protocol web services for internal use or our provided and consumed across the web via SOAP, REST, RSS, or ATOM protocols."
Read the entire "elevator pitch" by MS Platform Strategy Adviser John Mullinax, S+S is a BIG deal.
More wisdom on shared services from his blog:
"A rough, shorthand definition for the Services part of S+S is "capabilities from the cloud". This is sometimes call SaaS for Software-as-a-Service, and has been getting a lot of buzz. The attention is warranted: the web really has become a platform for building and delivering solutions. That's relatively new and very important.
While the web has indeed become a platform, it is not the only platform. The traditional software platforms are still around, and actually getting better all the time. At the heart of Microsoft's S+S strategy is the view that there's generally no need to choose either software or services -- rather all the platforms should just work well together and you should choose the set of capabilities that optimize value."
Saw this Love letter from a former colleague on Derik Whittaker's blog. Sorry to be posting only humor out of the gate, but heck, it's the holidays. Lighten up 
Too funny not to link here. Okay, I'll steal the graphic too...
