If you have visited Cocoon GT, you might have seen a Cocoon 2.2 Classic presentation. It shows an approach, and explains the steps one should do in order to upgrade existing Cocoon 2.1 application to Cocoon 2.2 with minimal disruption to application and your existing development environment. In essence, it shows how Cocoon 2.2 can be used in old Cocoon 2.1 way - and still allows you to use new features like Spring components, Spring XML files and cocoon.xconf file configured with property files, per-sitemap Spring beans and Avalon components, and the rest.
This presentation now is available here in several formats: