First, Ray Ozzie's fingerprints are all over this document. The Wizard of Oz, Microsoft's chief software architect, may be among the savviest technologists alive today, and it's been interesting to watch him navigate a huge, resistant bureaucracy. Since Ozzie's arrival after Microsoft acquired his company in April 2005, he's attempted with limited success to engineer a revolution from within.
Maybe it's because Ozzie is at heart the developer, par excellence, that he's pushed for a more pragmatic way to satisfy customer demands. He understands that the trend in software development is toward more composite applications. That is, programs built with feeds or the ability to be built using other apps. Along with data portability, these attributes now appear near the top of user wish lists.