I'm new to Cross and am narrowing down choices on a cross bike. Is there any real advantage to having a carbon fork in cross as opposed to aluminum or steel. I know that carbon might be a tad lighter but I don't know if it'll really add it ride quality on a cross course. It seems that in a race situation you're on and off the bike enough where damping road vibration isn't a major consideration. Any thoughts?

The relative low pressure of air in most folks' cyclocross tires will mask most of the effects of any fork you choose. You should worry more about getting the correct fit and if this is your first cyclocross bike, make sure you enjoy the sport (this is not clear from your one post) before buying a bike.

I think weight is the primary concern for most when they decide to go with a carbon fork.

Carbon fork- I have one now on my Salsa and it rides damn good. It's way stiff but does a good job of evening out the bumps. Feels like a road fork.

Alu fork- Had one on the Jamis and it was fine it the twisty single track I ride, but was very buzzy on the road, dirt, gravel or otherwise.

Steel- Had one on the Kona and it was probably the best riding of the three, or at least equal with the carbon. Stiff yet compliant and no ill effect on the road.
Of course it was a tubular legged Kona P2 fork and not some unicrown Surly noodly POS.

Just get carbon and be done with it.