If you are excited about managed add-in development and Outlook 2007, you've no doubt heard about the CTP release for VSTO v3 (VSTO is Visual Studio Tools for Office). This release enables developers to start working with managed code add-ins using the VSTO environment and targeting Outlook 2007.
Of course, this VSTO release is very early in the cycle and not all of the features are code complete or event included yet. This release is primarily targeting the runtime environment and making sure that things work. The side effect of this is that some extra "glue" is required to use some features. Andrew has a nice post over on his blog about how to use Form Regions with VSTO v3, so if you are interested I'd suggest you take a look.