Are in-wall speakers worth considering?

We're adding a family room to our house. It would probably be the best room in the house acoustically, but there will be too much going on in there to set up normal speakers properly. Are any in-wall speakers capable of providing decent sound?

The room dimensions will be about 14'W x 17'D x 9' H. The listening couch would be on the long wall, and the speakers would be mounted on the opposite wall (that is, firing across the shorter length of the room) and would have to be almost 10' apart due to placement of doors and windows. The floor will be carpeted. I'm sure I could squeeze a subwoofer into the room.

Thanks for any suggestions!