Ken Case on Omni's Plans for 2013:
Automatic document syncing is almost here! We call it “OmniPresence”: your documents, synced everywhere you want them to be.
We’ve designed OmniPresence around open web protocols, so you’re welcome to use our free Omni Sync Server or to host your own cloud server. We think that the option to host your own cloud is important—not just because of concerns with respect to privacy and security (though that’s key for many businesses), but because it means you can keep that cloud running as long as you want to keep using it. As we saw with MobileMe shutting down earlier this year, individual cloud services can easily disappear as business models change. Building a solution around open standards means that our customers have a choice of hosting providers rather than being tied to a single ephemeral cloud solution.
I want this very badly. I tried taking a stab at this a year ago with a little app named "SyncDAV" which was basically like Dropbox over WebDAV (the intent was for VP5 users to use it since I took out WebDAV syncing). But syncing is hard and I had more important things to work on, so I eventually gave up in favor of just telling folks to use Dropbox.
I also find it telling that iCloud isn't mentioned in Ken's post at all.