How amazing would that be?
On that note, I think the Coda ‘Doc’ terminology could be confusing to people given their existing mental models of Docs. To me, the Coda Doc is more like a space - people need to understand how much stuff they can keep in one Coda Doc (lots, which is awesome) but the real-world parallel does not help with this.
To replace Confluence (please please when will it happen) I think you need to cater to the IT managers - who we must all deal with. SSO is the trick there - most seem fine if that is done properly.