However, when I started a new project using WCF it got interesting, I could build already made WCF projects, but System.ServiceModel (and System.Runtime.Serialization for that matter) was nowhere to be found in the Add reference... dialog.
As I also do fiddle around with msbuild stuff I figured that I could work around this quite easily by firing up the project xml file (right-click the project, choose Unload project, right-click the unloaded project, choose Edit
and add the missing reference to the project by hand
<Reference Include="System.ServiceModel" />
Still, I thought it was kinda funny that the workaround was needed.
EDIT: This is not an issue anymore since Orcas CTP for RC1 has been released.