I'm not laughing at your picture, but it's funny because that's exactly how I got started on my project, I made a somewhat large hole in my wall to see what was back there. I just kept cutting.
Eventually what I did was to remove the entire drywall from the mantle up to the ceiling, removed the mantle, removed the bricks. I reworked the studs to be 16" on center so I could have good support for the plasma mount. Then I ran 2" conduit from the attic down. Is that an outside wall? The insulation is confusing if not (but of course I live in Florida so generally only the outside walls are insulated, maybe it's different up north).
Anyway, my point is that maybe you don't want to give up just yet. I ended up putting some built-ins on either side of my fireplace for components and tiled the fireplace (instead of the brick). Looks much nicer and probably added some value to my home. The last piece is yet to come, the plasma, but soon...
You didn't mention what the rest of the room looks like. In my case the fireplace is the center of the room so having the TV anywhere else did not make sense. Maybe in your room having it on a different wall will look good and ease the wiring.