The development team I'm working with will be moving to .NET 4.0 soon, however, the data access class library we use still uses ADO.NET "classic", meaning SqlDataReader, DataTable, and the like. Meanwhile, it seems like Microsoft and probably the rest of the world is moving forward with Entity Framework and WCF Data Services. I didn't find anything on MSDN that indicated which of the data access technologies Microsoft considers best practices.
Does Microsoft have a preference? What data access are most people using currently? Are there good reasons to stay with ADO.NET classic and not move to Entity Framework?