I've run into the same problem with wscf.Blue and VB.NET projects. It looks like there is a problem/bug in the way the .SVC file is generated because it is missing the Project Name in the Service attribute, so the service Type can't be found.
Luckily, there is a simple workaround for this issue.
Add the project name to the service attribute in the generated .SVC file
The format is ProjectName.Namespace.ClassName
For example, change:
ServiceHost Service="Namespace.Service.SampleWCF" %>
ServiceHost Service="ProjectName.Namespace.Service.SampleWCF" %>
There is another workaround related to this issue. When displaying the .SVC helper page, you may see a message "Metadata publishing for this service is currently disabled". This usually shows up
when you don't have a MEX endpoint defined. However, even after you add the necessary settings for the MEX endpoint, you may still see this message.
It looks like there is also a problem with the way the output.config settings are generated, because the service name attribute is missing the Project Name as well.
To fix this, add the Project Name to the the service name attribute in the
thinktecture folks, can you look into these problems with VB.NET projects?