The system employing cement board with a skim finish is sort of going around one's ass to get one's elbow. A direct application of Portland cement plaster, i.e., stucco, to the brick masonry is the easiest way to make this fireplace look like concrete. It can also achieve the effect of concrete when applied properly since stucco is in essence concrete.

A good plasterer can give you a polished surface by employing the appropriate fine sand aggregate in the finish coat and troweling properly.

A good plasterer should also be able to color Portland cement to suit your tastes.

Bo...I anxiously await your photos!

mordo: while true, I hate to see brick permanently covered. The nice thing about backerboard is that future homeowners can always revert to the original if so desired.

Personally, I like brick. It feels 'loft-like' and would fit into a modern decor. That said, there's lot of kinds of brick fireplaces, some looking better than others ;o)