They seem to be opening a crack for Microsoft on the desktop, a crack that Microsoft could well take advantage of.
You don't see major corporations abandoning their e-mail infrastructure, but they are beginning to seek outsourcing to handle things like remote mail and calendaring, ... Messaging Online.
These firms are still in foot-in-the-door mode. They aren't getting entire companies to outsource: They're getting divisions and bits and pieces,
The future of junk e-mail is that you need a receptive audience,