It looks like Windows Server 2008 needs to be extended to be able to host WCF 4.0 and WF 4.0 type of applications. The codename of this set of extensions is called Dublin. Dublin is the capital of Ireland and I'm curious if the author of the codename knew about that. Anyway, you can find more details about the new platform here. At the first glance it looks interesting but still there is no mention of publish/subscribe type of messaging. I hope I've missed something as this a huge gap in the communication framework that Microsoft provides.