But I might be biased...
Non-technical people don't seem to get to the step of generalising what they know about using computers, i.e. Word->word processor and Excel->spreadsheet, so going to something new like Google docs isn't like "oh this is an online word processor like Word" but instead go "this isn't Word OH MY GOD WHAT DO I DO?"
If something could map say a "My Google Docs" folder under My Documents it would be the same; so you can just go into Word and open a file up for editing.
Personally I'd rather just open my browser, but hey I've used several word processors as well :P
You can hardly move on the Internet for 'simple' collaboration websites.
Point to one that also integrates with Active Directory and is backed by SQL Server and hooks document libraries into Outlook and
posterous:blogging :: ???:sharepoint