Thanks for writing us. Currently, we do not have plans for a new edition of ADO.NET in a Nutshell, but thank you for letting us know you'd be interested in one.
Although they are not the same kind of reference book, we do have some more recent ADO.NET books:
ADO.NET 3.5 Cookbook, 2nd Edition
Professional ADO.NET 3.5 with LINQ and the Entity Framework
Microsoft® ADO.NET 4 Step by Step
Programming Microsoft® ADO.NET 4