We are investigating using Visual Studio 2010 for developing Outlook
addins.

It appears that VS 2010 cannot be used to develop addins for Outlook
2003 as mentioned in the link below:
http://msdn.microsoft.com/en-us/library/bb772080.aspx

Is this true?

At this stage we are thinking of creating the addins as Shared Addins
instead of using VSTO.

Would appreciate any guidance from people already using Visual Studio
2010 for developing Outlook addins that support Outlook 2003, 2007 and
2010.

Thanks
Sanjay