The problem is that to do per-install tokens, one needs a secure side channel between the server and client over which to exchange these tokens, or a secure sid

The problem is that to do per-install tokens, one needs a secure side channel between the server and client over which to exchange these tokens, or a secure side channel to some kind of key management/federation server. That's fine and good, but it completely defeats the point of OAuth 1, which was to provide a request signing method that didn't depend on any other secure side-channels to operate. With OAuth 2, of course, the point is mooted a bit by the decision to go with HTTPS as the secure channel, and such a scheme seems much more plausible.