Pleasure stu, I just happen to know some friends who've had a designer remodel their lounge not that long ago, and have buried composite cabling in the wall from the hifi cabinet up to their projector.

They now have a HD projector and prehistoric cabling which can't be changed unless the expensive bepoke wall paper is torn off the wall
Stuck with crap picture quality for the sake of some good design.

If the wall is brick wall, you may be able to create some form of trunking or channel on the wall (thinking shallow wooden box or something), rather than in the wall. It would be on show obviously, but, would be future proof.