After the announcement last week of this great piece of technology, we can finally all start to talk about it. Although you can code directly against the WWF, it contains a nice example of a couple of graphical DSLs that allow the developer to declaratively describe workflows consisting of human and system activities. The lead architect for WWF, Dave Green, has started a blog here, but you'll also want to check out a great article written by David Chappell published on MSDN here.