David Overton has a blog post describing how folks with SBS can make a few updates so they get the new icons registered with the new extensions (as well as proper behavior with the open control): http://uksbsguy.com/blogs/doverton/archive/2007/03/13/how-to-get-companyweb-windows-sharepoint-services-v2-to-work-with-office-2007.aspx

As David mentions in his blog, this helps with the following problems:

  • no icons for files
  • file types not recognized by companyweb
  • downloads could not be opened as the file type was said to be a compressed file
  • could not edit from companyweb