- Authentication is via facebook. There appears to be no obvious way to link docs.com to an existing windows live account
- Editing feels to be as responsive as Google Docs, and perhaps a little better than Zoho
- Documents can be printed on a local printer
- Documents can be shared, but only with existing Facebook friends, but each document has a public url that can be given to other people to allow them to access documents providing they have a Facebook account. I havn't tested what happens - my test document is at http://docs.com/8O5U.
- Documents can be downloaded and opened locally with Office in a single click operation. There do not appear to be other export/download options
- The interfaces are Office 10 like with a tabbed structure
Probably not, personally I'm happy with Google Docs for my lightweight wordprocessing and spreadsheet needs, but given that with some of the 500 million Facebook users using Facebook to the exclusion of other services it's an interesting and useful edition to the Facebook ecology.
I imagine we'll start to see documents created in Docs being submitted as part of student assignments etc in due course ...