The video you see to the right is the latest Halo 4 trailer. In case you weren't aware, Halo 4 is releasing on November 6th, and while it should inevitably sell an insane amount of copies, many gamers have been hesitant to jump on the bandwagon.
Why? Simple - new developer.
Yes, 343 Industries has taken control of the Halo franchise as Bungie has now gone their separate ways. There's really no reason to be alarmed here however, as 343 Industries was created by Microsoft themselves in 2007. They have reportedly been working on Halo 4 since 2009 as well, meaning they have had plenty of guidance from Bungie, as well as plenty of time to create something truly special.
Despite all that, just watch that trailer again. If that doesn't solidify your decision to buy it then nothing will.