It would be cool if some of the large level designs in some of these games were made more widely available to other developers. They could sell it, doesn't have to be free. Seems like it could be a decent business model.
This is the thought that really stuck with me from the article. Even if it were through some kind of marketplace, couldn't developers share assets for reuse across different games? You can't tell me that an asset can't be retextured or an animation tweaked to apply somewhere new and be virtually indistinguishable for a fraction of the cost of creating it from scratch.
I believe that store is for individual assets rather than whole levels with the assets already arranged... But I'm not certain because I haven't used it.