IBM understands that a lot of important business collaboration occurs across enterprise boundaries.
This kind of cross-organization coordination will become increasingly important. A distributed world requires distributed approaches to security.
This is a very powerful tool, potentially with a bidirectional metaphor. It's indexing all this stuff on your desktop and doing something on the Web. Who's to say that's not a potential breach?
It looks a bit like Microsoft stalling for time, as it readies for the bigger battle.