If all of that facebook-page-type-stuff was saved on the wart, then we wouldn't be prevented from browsing through it while they were personally offline with their computer powered down. I assume that would be the plan - but if I'm wrong, I would share your doubts about this catching on as a drop-in facebook replacement.

-edit-

To be clear, I'm imagining pictures, an activity stream, a presence server, and maybe a calendar and a blog sitting directly on the wart - independent of a separate computer to such an extent that a person wouldn't even have to own an actual desktop or laptop to use the appliance to its full extent, maybe just a cell phone app to update these things, or even updating them through public or other people's computers over the internet. If friendly neighbors left their freedomboxes open to your through traffic, it might not even necessitate a local internet connection.