No, not the white fluffy objects up in the sky.
Halo 4 will be the
first game to utilize Microsoft's Azure, which is Microsoft's cloud services. With the scale of the game, 343 Studios decided to build it with a platform that can scale up and down.
With Azure, you pay for usage so when it's not at peak times or you have very little users say at night, costs can be relatively low. Also, if for some reason you get a ton of users on at the same time, Azure can scale up to deal with these situations.
It's a cool technology and it's good to see that it's being put in a game. I'm sure Halo 4's going to have a ton players in the first few months and slowly trickle off. I'd love to hear the usage statistics in the next few months and how Azure helped manage the traffic load that the game generates.