Completely addicted. I downloaded the demo 2 days ago and have already played 3 times. I went through on each difficulty and have been sufficiently impressed. There will be the familiar personel and vehicles we all remember and love, such as the LAAG type Warthog (scout), the marines, and the Scorpian tank. There will also be many new things to look forward to. A 6 wheeled anti-vehicle called the Cobra, plus a missle truck, the Wolverine. There will be a new plane, the Vulture. New men with flamethrowers and upgrades available for all of them. Best of all, there will be spartans.
The story takes place 20 years prior to the original Halo in 2531, (making the chief 20 years old for those scoring at home) on the planet Harvest (see book #5 Contact Harvest) where first contact was made in 2525. You follow Sgt. Forge and try to figure out why the covenant are so interested in the planet.
The game itself is a stragtegy game similar to Civilization. You look down from the sky and command your troops to different locals, to engage enemys or to retreat, etc. You build bases and you army to suit your needs/tactics. Basically, you control them the same way a CO would, you don't do the fighting yourself, you tell others when where and how to do the fighting for you.
March 3rd can't get here soon enough!