The day after Orcas Beta1 appeared for public download reports appeared on the ADO.NET Technology Preview forum that the EDM Wizard (that is, "Add New Item/ADO.NET Entity Data Model) wasn't working. And, sure enough, if you choose "Generate From Database" and carefully choose which tables to use, you get a model with no entities. If you choose an empty model, you get "Specified argument out of range of valid values", and get the three mapping files, but no language file. What to do?
One way around this is to use the files generated from the March CTP wizard. Because the XML schemas for the mapping files haven't changed since March CTP, these work fine. In fact, all of the EDM code that worked with March CTP continues to work unchanged. That's what I used in the SQLCE and EDM blog entry posting.
If you can't keep an old March CTP around just to generate EDM Data Models, you can use the EDMGen.exe command line utility in the C:\WINDOWS\Microsoft.NET\Framework\v3.5.20404 directory. This utility appears to work and generates useable code. It also generates a richer model than the wizard did (with AssociationSets and Associations) but it takes a little more work to put together a project. I'll post a really simple one if there's interest. And EDMGen doesn't generate the same output as the wizard used to (for example, columns of type NTEXT are ignored in the model) and uses different default naming conventions. So at least there are a few workarounds for now.