What's Oslo?

Anyone who has come close recently with an XML'ish topic has probably heard me ask "Do you know about Microsoft's Oslo?" Well Oslo is now much more out of the closet but in many ways still as mysterious. At the root of Oslo is the contrast of imperative and declarative expression (program logic and rules). Complexity is the great issue in all forms of modern application and system design. The wise men all believe that moving more and more application and system design into a declarative form is critical (rules and their interaction are much easier to understand than code written in C# or Java). Oslo is a unique and bold tool for declarative expression. Or is it? I keep asking the Microsoft marketing people to give me the decision maker elevator pitch for Oslo (or declarative expression more broadly) and they can't (not because it doesn't exist but rather because they haven't coalesced it). Microsoft's PDC is the ultimate geek fest -- the lingua franca of PDC is on the fly construction of working code in demos. PDC certainly wasn't the venue to give the CEO elevator pitch. The pieces of Oslo that were explained at PDC are interesting to a programmer but I'm sure completely cryptic to anyone on the business side. People very much "in the know" had suggested that Oslo would be used for rule based virtual machine deployment and that didn't see the light of day (and now those in the know are less confident). I guess I'll just have to wait some more and see what transpires.