This is far less important than buffering for server>user events (which we now have), but it'd still be a big efficiency win - esp. for Ajax + for bandwidth minimization on mobiles.

It's even possible to offer this for events with callbacks if we're prepared to allow actual timeouts to vary by [0,<max-buffer-window-size>] ms.

UPDATE: Have started some work for this on the dev branch. Shouldn't be hard to implement, just short on time atm.