You read that title correctly! 343i really outdid themselves this time. Not only do we get a free map, but it's ahead of schedule too! You can download it from the Xbox Live Marketplace now! Gogogo.
If you haven't been keeping up, here's a sample of the new forge pallet you'll be seeing in Forge Island. Now, here's the real question. WHY ARE YOU STILL READING THIS?! If you haven't already booted up Halo 4 by now and started downloading this bad boy, I highly suggest you do so.
Also, I heard that some of you apparently have this thing called school? Not exactly sure what you mean by that, but in case you can't download the map right at this very moment, go to this page and you'll be able to queue the map for download, so as soon as you turn your Xbox on, it'll be ready to go!