For me I have a WCF service which acts as DAL and does all the CRUD operations
I just came to know regarding the new ADO.Net Data Service, just read somewhat but not actually sure when & where to use it?
Just to add more, my new project is in ASP.Net MVC, so is it wise to use ADO.NET Data Service rather than WCF service with it which will probably act somewhat like 'M'(Model) of MVC ???
One big advantage is that with the ADO.NET Data Services, you don't have to specifically write all the services for basic CRUD operations as you may with WCF. Since ADO.NET data services basically expose those operations, you can focus more code writing and debugging on business logic.
First, my advice would be to write your MVC code so that it is oblivious to what the back-end data model is. Abstract away any dependencies right from the beginning.
As for deciding whether or not to use WCF, I'd suggest that you decide whether or not you'll want to reuse the data component that you write. If you have plans on using your data code in a Silverlight, WPF, or any other format, then I'd suggest sticking with WCF.
Also, remember that you can always simply wrap the ADO.NET data services with a WCF component and still enable the reuse scenario. Get the best of both worlds!