Getting Ribbon XML Intellisense in VSTO 2005 SE
Here's a tip--to get Ribbon XML Intellisense working in VSTO 2005 SE, copy the file
\program files\microsoft visual studio 8\Xml\Schemas\1033\CustomUI.xsd
to the folder
C:\program files\microsoft visual studio 8\Xml\Schemas\
Happy Ribbon Hacking!