I kinda like that idea. Currently, the idea of the digest email is to bring users back to the forum. But perhaps the digest has value beyond that? Perhaps the /top pages could be modified to look more “social”? (Contentwise, what is the difference between how the Top listings are generated and how the digest mails are generated? Digest mails are obviously more personalized, but how exactly?)
Another avenue could be to build on the digest preview that already exists for staff and simply give users access to their current digest.
But I also have some doubts, both regarding the digest page idea and the idea of making discourse more social.
As for the digest, I think it is crucial for bringing back people to the forum. But if people start using a digest page as their home page on the forum, I think there is a risk that this will pull attention away from the “long tail” and towards the mainstream of the forum.
As for discourse as replacement for facebook etc, this has been discussed in various other topics, so I’ll just briefly mention it here: a key difference between FB and discourse is obviously that discourse is topic focused and FB (and Twitter even more so) is relationship focussed. Perhaps there is an assimilation going on (given that FB is pushing it’s groups feature and here on meta the feature request of following people comes up repeatedly (and whether that assimilation is good or bad is a different question), but at present, I don’t really see how discourse could replace FB (especially as long as the discourse hub idea is on ice), because it’s quite different. That said, I wholehartedly endorse that