Recently we did MS CRM 2013 beta migration upgrade for one of our organization, where we have multiple plugins and lots of Java Script web resources with custom Silver light web resources. We have done our customization in classical forms. To upgrade we followed below steps
Step1. First we took full backup from our old Database server.
Step2. Restore organization database to MS CRM 2011 beta server.
Step3. Imported organization using deployment manager.
Below are the changes between MS CRM 2011 and MS CRM 2013 beta organizaton