Sharing screens with other brands is quite normal and does NOT mean that a Samsung is the same as a Sony but cheaper. Far more important things such as the quality of processing have a huge impact on the finished product. The Bravia Engine is what makes the Sony LCDs what they are and that technology isn't used by anybody else.
To put it into perspective, Loewe and B&O both use screens from cheaper brands too, and Pioneer's LCDs use Sharp screens.