i think in the future there will be more episodic games, but they would be more like TV shows by having longer seasons and advertisement so that it can be sold at a reasonable price.
when i first played mass effect i though this would make a great episodic game (like star trek) where it could still have an open universe with procedurally generated content (side quests) but every week-month there would be a release of the important story missions.
and of course a similar thing for adventure games but without the persistent world just episodes each week-month.
but i think the only way this would actually be affordable for people to buy is if the finance of the game wasn't purely people buying the episodes but also advertisement in game, so it would be like a TV show in that it doesn't rely on DVD sales to get it made.
i personally wouldn't mind advertisement in games eg. loading screens sponsored by redbull or some in game product placement.
or possibly there could be some kind of network subscription like cable TV that would be sponsored as well.
what do you think the future of episodic games will be? and how do you think it could be done?