perplu: you don't get any return on the built-in speakers when you sell a house
Sometimes it's quite a negative, in that you can't reconfigure a lounge room etc once the TV is mounted and speakers are installed.
You may want to consider a way to dock with ipods etc too, so people who have their own music devices can use them in their room, rather than select from your music storage. Long term they'd just add their music to yours though I guess.