Today televisions and projectors are manufactured in a way that gives the owner the freedom to chose how he will set it up and in the event that purchasing a television set for example may come with the thought of getting a wall unit that in turn will takes up the much needed space that a playful child would have loved to freely run without knocking a toe or two on the new barrier's wooden edges.
Unlike the older television sets that used a Cathod Ray Tube that made them bulky and stable at the same time todays plasma television use Liquid Crystal Display hence its slimmer and lighter and with the standing base being a portion at the centre,its less stable as compared to the CRT.
With its hefty price and stability in mind many users have prefered to SECURE it on the wall.this also has an aesthetic value and more space and light is available that would have otherwise been taken by a dull wall unit.
Having it hang on the wall has been an obsession to many plasma owners who went ahead to try their luck in the mini-extreme-make-over which yielded extreme damages.Its good to Do It Yourself....even the professional does it himself.... but the only difference between you and the professional is that he has gone through the hands of experience who still is the best teacher and becomes perfect with every set up.
So unless you can put your money where your screen is don't Mess It Yourself.