Consider the following code:
var Products_First = (from Entities.Product p in myContext.Product select p); Entities.Product newProdu
Properties of type ObjectQuery, like myContext.Product, always query the DB. That's what they do.
ObjectQuery
myContext.Product
In EF 4.1 you can use DbSet.Local to query memory.
DbSet.Local
In EF < 4.1 you would use:
ObjectContext.ObjectStateManager.GetObjectStateEntries(EntityState.Added).Select(o => o.Entity).OfType()