I like the way they release the episodes, and actually think it is a very smart development and release set up. I think this sort of set up would work wonders for AAA games that suffered last gen due to low sales. If they released like 1-5 levels of an SP game for $20 and every next batch of 5 levels for the same price the more content the more people are paying for the game. Also if the game is to have a MP portion then maybe a bigger up front cost, or separate cost for that portion.
If you hadn't noticed, this is Forum 2.0