For those of you who are cruising along on your last years knowledge of xRM development habit you might make a note to add a task to your to do list!
SDK v4.0.13 (and SDK v4.0.12) offers NEW options and CHANGES old accepted xRM development practices
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.
In addition to the documentation, this download package includes the projects for all sample code found in the documentation, and full featured samples that are not included in the documentation. The package includes a visual style guide you can use to make your customizations fit in smoothly, and a style sheet you can use as a basis for your work. There are also tools and helper code provided in this package. Look for regular updates to this SDK!
So now that you have completed all your New Years Resolutions (or abandoned them) take a bit of time and do a bit of deep diving into the new v4.0 SDK
and for those guru, gurus who are developing on the v2011 platform. The same applies :) as many of the new concepts within the sdk world made it into the v2011 SDK world as well.