For example, Fable 2 pub games, if you remember, allowed you to earn money and items for Fable 2. It sort of fell short.
Dead Rising 2 had a downloadable release as well, however, instead of a collection of mini games, it was a full downloadable game made with the Dead Rising 2 engine.
The Skyrim game would likely be something more similar to how Fable 2 handled it.
The question is, if Skyrim came out with a Downloadable game in September/ October, would you buy it?
Also, what kind of game would it be? Minigames to earn money? Or perhaps a little playable prequel to the full game?