VSTO and Security
VSTO (Visual Studio Tools for Office) is a powerful tool used to have the power of .NET framework insode an Office 2003 document (Word, Excel, Outlook and InfoPath).
The only, and most important, limitation I can register is from a security point of view. The documentation says: "To deploy and run an Office solution that uses managed code extensions, you must grant full trust to the assemblies in the security policy of each end user or computer. If the document is in a network location instead of on the user's computer, you must grant full trust to the document as well."
From a policy company point of view its unacceptable to give full trust access to office assemblies. I hope this will change soon...