Very timely brand spankin' new whitepaper has been published on MSDN: http://msdn.microsoft.com/en-us/library/dd200919.aspx
Nice job of tying WF, Oslo and Dublin together for the big picture. You will notice what I think is becoming a theme in messaging around 4.0 marketing which is placing a much bigger emphasis on WF than WCF. That is probably fair, as WCF owned the spotlight in the .NET 3.0 release, but I believe we will see more and more focus on WF as WCF takes a back seat in this release. To be sure, however there are great improvements in WCF coming our way including full schematization ala WF, new bindings and performance/persistence patterns.
David does a great job covering Dublin. My synopsis is that Dublin is COM+ application server (throttling, persistence) and BizTalk admin (tracking, HAT, etc) packaged up for WCF and WF and integrated into IIS 7 management tools.
More to come!