Microsoft have released a new version of the MSCRM SDK, notably with new extensions to support different development paradigms for LINQ and using automatic code generation to build Business Logic Classes for use in custom ASP.NET extensions to MSCRM.
“This release includes the new Advanced Developer Extensions for Microsoft Dynamics CRM, also referred to as Microsoft xRM. This is a new set of tools included in the Microsoft Dynamics CRM SDK that simplifies the development of Internet-enabled applications that interact with Microsoft Dynamics CRM.”
MSCRM SDK 4.0.12 can be downloaded from Microsoft.com
This looks to have the potential to revamp how we write code to extend MSCRM with the use of automatic Connection Strings, Classes and LINQ Queries; could be a while between current commitments before I get chance to put these into practise in my projects, however will certainly post articles here when I do.
CRM Consultancy Blog 
CRM MVP David Jennaway on CRM SDK 4.0.12 and the Advanced Developer Extensions – good breakdown of the new SDK elements.
http://mscrmuk.blogspot.com/2010/05/crm-sdk-4012-and-advanced-developer.html