Yes it's true!
Today our expert TV installers wall mounted a 51" 3D TV onto an internal static caravan wall and it looks great!
We hid all cables and connected it to an xBOX 360 with konnect, blueray player & even installed a new aerial point.
may we just point out that this is probably not recomended for D.I.Yers you need a certain degree of skill and knowledge to even attempt this, and other companies would probably say it wasn't do'able, but we say Rubbish! we'll mount TV's any where if possible and today we proved it.