DbContext book is online!
The digital version of Programming Entity Framework: DbContext is now available directly from O’Reilly Media at http://shop.oreilly.com/product/0636920022237.do.
The was a nice surprise since production only sent the final manuscript to the print production department yesterday.
The print version might be another week or so.
Amazon will most likely have the kindle version available sooner than they are able to ship printed copies.