Microsoft has recently revamped the VSTO online learning center which looks very good to me. The site provides information and knowledge about VSTO and how to use it to develop Excel, Word and Outlook solutions and also how to deploy the solutions. From my point of view it’s welcoming as I know that many developers are interested in VSTO but lack the basic information and knowledge about VSTO.
The startpage is available at Office Development with Visual Studio.
The Excel section can be accessed directly via Excel Solutions with Visual Studio.
Perhaps these pages can make VSTO more understandable (and also get a better reputation) in the Excel Development Community? After all, knowledge is the key to all new areas.