If you use one of those new fangled "cloud gaming services" - more specifically, if you use OnLive, they've got a great deal going on if you want to play the new Civilization V expansion pack. If you purchased Civilization V: Gods and Kings for the normal price of $30, they'll throw in the base game (which is required) for free.
You should have full access to the local multiplayer of the game, but it looks like the online co-op is going to be disabled. As a reminder, you'll need a fast broadband connection and the OnLive Console, a PC, or another device that supports the service.