Entity Framework 4.0 Improvements
First up, let me just say that I’m quite pleased that my needs with respect to declaring my fetching intentions (eager and / or lazy), no longer will require the assistance of 
PostSharp to get the job done. PostSharp is a great tool but I really shouldn’t have had to use it to achieve working the way I wanted to, therefore POCO is a welcome addition even if it does force me into some things such as choosing ICollection for 1..M navigable relationships within my Domain Model (only if you want to use change tracking proxies).
I am not going to regurgitate the changes here, for a complete list of the changes and new features see the ADO.Net Team blog.
There seem to be several points along an axis of how POCO you can choose to be with Entity Framework 4.0. At this stage I have the feeling that I will fall into the camp that probably wont use the proxies for change tracking but I will reserve judgement on that and perhaps that decision will be best left as a case by case assessment for some.
The thing I like the most is the fact I can (as already stated) remove the smoke and mirrors from my past efforts to get (somewhat) transparent lazy loading and streamline my whole approach. I say ‘somewhat’ transparent due to the fact that DeferedLoading is still ultimately ‘opt in’ and hence if you wanted to be pedantic you could make a case that this is still explicit. See below.
context.ContextOptions.DeferredLoadingEnabled = true
I will follow up from this post will several more by examining each constituent part in the new version of NFetchSpec for the Entity Framework version 4.0. NFetchSpec4Ef, provides a reusable approach to implementing Repositories, Fetching Strategies and Specifications. Fetching Strategies provide a unified way of declaring your intent when instructing the Entity Framework to fetch data. Specifications enables a functional approach to supplying dynamic query predicates and stays true to the patterns original intent, that being to provide a means to testing that an entity satisfies a given set of conditions. Repositories speak for themselves.
