I watched an HGTV episode recently where they placed several layers of compound right over the brick; sanding and smoothing in between coats until they achieved the desired surface. They then built a surround with mulitple layers of MDF and built up a molding. Inside the surround they laid out a light colored stone... something like a flagstone. On either side they built white open shelving to house home theater equipment. Sounds a little like what you want. Now... I'm a HUGE fan of glass tile but once you do it... you're kind of married to it due to expense. The beauty of this "spackle" treatment... is you can change out the color, making it an accent wall or blend it in with the existing cabinetry giving it a real built in look. The episode was pretty cool because the chiseled out the stone to create a thick deep enough groove into which they laid tubing through which they ran the all the wires for the home theater equipment. So many ideas out there.....

The two looks you posted are very family room casual - is that where you are going? The mantel you have is pretty formal in design, so I am wondering if your decor and the rest of the woodwork in the space are equally formal? I don't see either one of those working in a more formal space. A wonderful textural slate could be terrific, though.

Here is a photo of the fireplace. Not sure why it wouldn't let me post it with the original post.

Oh, for symmetry, a long vertical art work, or a pair of complementary art works hung vertically on the right to the height of the bookcase top would balance out the bookcase. Or hang several floating ledges in white to display more artwork with top shelf at height of top of bookcase. This fireplace also has a gorgeous frame. (Probably there was a mirror inside that frame at one time. If you had some budget, you could get an antiqued mirror fitted in there. $$$$)