Most of the pro installs I've seen were done to hide the wiring, or the person that had it done was really clueless about tools, etc, or just had the cash and didn't care. A friend and I put mine up in about a half hour just by putting 4 screws into the studs.
I did see one recently, where they cut a piece of 3/4" veneer plywood that was just the size of the set, and put molding around it like a picture frame. it was stained and finshed really well and the mount lag screws were replaced with bigger/longer ones and the whole thing was screwed to the wall with 6 big screws. It looks like a painting on the wall, except they have a HTPC running a million pics of their dogs and kids, etc on it. The wiring was hidden too. That guy makes his own furniture that matches anything you've ever seen in a store.
Too much work for me.