Cracked.com tries to make some predictions on what we can expect in the next 25 years from the gaming industry. They start with Spore, a gaming which is expected next year:
This sounds like a ridiculous crack fantasy to any gamer who's ever dropped $60 on a game and blown through all 12 levels in eight hours. How the hell do you fit an “infinite” number of planets and aliens on a few DVD’s worth of data?
The answer is a technique called procedural generation, which just means the game doesn’t have to store millions of creatures, it just stores the methods by which they can be built. You, the gamer, make the creatures.
Your malformed abominations, along with all the civilization and technologies that spring from your deranged imagination, are automatically uploaded online where they become part of the Spore universe. Those other planets you get to travel to? They're all created by other gamers.