No, it's not quite what I had in mind. OStatus is intended for exchange of updates between sites that have statuses (statii?), while I'm thinking of something that would exchange messages between users directly without the need for a central server (except probably for user discovery and connection).
Actually, XMPP the underlying technology we finally decided upon, just before the team fell apart. But the concept was to make a product that is based on it, but with a different feature set from the usual IM/chat clients we see.