It seems like the obvious thing to do is to create a standard, perhaps based on however Reader currently syncs, and then build against it. That way, people like me who aren't interested in e.g. "social" features or "sharing" could implement a simple backend, point our preferred clients at it, and call it a day. Let the client developers war it out over front-end features, and let clever people like the Newsblur fellow add cool new backend stuff.

Wishes, horses, riding beggars, &c.