Here's the problem I see with wall mounting:
WHERE DO YOU PUT ALL THE CABLES AND COMPONENTS? Unless you do nothing but watch boxless cable or OTA off an antenna, you still need SOMEWHERE to put all the cables. Unless you want to take the time to develop a convoluted system of running all the stuff through the wall to a cabinet in another part of the room, where to you put it all?
With the latest flat panels, when you have a wall mount, all you need is power and one additional DVI cable. Sure if you have multiple inputs/outputs it gets more complicated. Yes, you do have to cut holes in the wall. I just wall mounted a 27" LCD in the kitchen/eat-in dining area and with interior walls it's pretty easy if you're a DIY type.