Today, a new Halo 4 trailer highlighting the Covenant weapons featured in Halo 4 was released. Despite their civil war and the destruction visited upon them by Master Chief in previous Halo games, the religious aliens will be back to serve as more cannon fodder for Halo 4.
A similar trailer (featuring a similar dubstep score) was released more than a month ago that features the UNSC weapons in Halo 4. And though the specific weapons of the new vilains, the Prometheans, haven't gotten their own trailer yet, a bit of their technology was revealed in a video documentary about them.
One major change to the Covenant arsenal is that the plasma rifle has been replaced with the new Storm Rifle. Other than that, several classic covenant guns have gotten a revamped design. Halo fans will instantly recognize slightly modified versions of the Covenant Carbine, Beam Rifle, Concussion Rifle, Fuel Rod Cannon, Needler, Energy Sword, Plasma Pistol, and Gravity Hammer.
Speaking of gravity hammer, it was revealed at Pax Prime a few weeks ago that Grifball, the football/soccer-inspired Halo eSport, will be a multiplayer mode available at launch.