The only things I see is viable for "cloud" computing are typically background stuff or "asynchronous" operations.
1. In a open world game, the sections the player is not currently inhabiting could live on and create dynamic situations (town built/destroyed, npc fighting, alliances being created, persecutors catching up to you, etc).
2. Connectivity with other players, trade, chat, etc.
3. Pre-loading/Streaming next level (no load times). Also possible to "prepare" complex random generated worlds, etc.
4. Have assets in the "cloud" (textures, voicesover, advanced AI)
5. Some other stuff I haven't thought of.
How well this is implemented and how much this will benefit the end result is a different matter. Guess we'll have to wait and see. I am guessing a wast minority will use it to actually improve the performance or scope of games.