Make sure you have some free space.
Microsoft Announced today that players will need at least an 8GB USB Stick to play Halo 4, so those of you who are somehow getting by with 4GB on your arcade consoles are going to have to upgrade.
At a minimum, you’ll need at least an 8GB USB Flash Drive or an Xbox 360 Hard Drive to play Multiplayer mode in Halo 4. For an optimal experience playing with an Xbox 360 Hard Drive is highly recommended. For Xbox 360 4GB, Arcade and Core consoles, the Xbox 360 Hard Drive is sold separately. See below for more details on the storage device options available for Xbox 360 and Halo 4.
At least they’re giving you a few months to prepare. Are any of you Halo fans still running without some sort of additional storage anyway? For more info on how to get yourself some additional storage you can check out the announcement here.