I tried to tackle the same thing in CTP3, but I was unable to resolve it. Using CTP4, it was about as easy as I could wish it.
Just for fun, the following screen shot looks like it contains a bug, but it doesn’t (at least, not to my knowledge). If you can spot what the bug is, I am going to hand you a 25% discount coupon for EF Prof. If you can tell me why it is not a bug, I would double that.
As an aside, am I the only one that is bothered by the use of @@IDNETITY by EF? I thought that we weren’t supposed to make use of that. Moreover, why write this complex statement when you can write SELECT @@IDENTITY?