I'm somewhat confused, is this a different effort than the royalty free codec which is being developed by Google, Amazon, Netflix, Microsoft, Mozilla, Cisco, Intel under the name 'Alliance for Open Media' ?
Regarding the video codec, it's the same thing, except one in IETF is the actual engineering group, and that AOM is more of an administrative one that synchronizes all the bureaucratic stuff probably (legal as well I guess).
UPDATE: See here: http://xiphmont.livejournal.com/67752.html