I think it's better that all the pieces are developed in parallel. Trying to architect all the pieces required into one project would be a huge mess. Additionally, we're not sure how it's all going to fit together so we'd be wasting our time.
On the subject of video codecs, I know of two people that are writing high performance video codecs from scratch. One of them is me, the other is a secret. Four months seems to be a reasonable target for the fruits of these efforts.
- Aaron Holtzman