This really depends on what you mean by "converting 2D to 3D". For games that are 3D already, but never tested with a 3D display, they usually have "artifacting" problems. These are either objects or characters which are rendered via "sprite" methods of the old 2D side-scrollers, or even Wolf3D/Doom era. A sprite is, by nature, 2D. And when a sprite is used, it will be flat. If the sprite is placed inside a 3D world, you'll see a flat surface at the correct depth. Imagine, if you will, a 3D game where the enemies are made of cardboard cutouts and they move around in the level. Another common issue is incorrect depth. Sometimes, game developers add "features" to the post-rendered image, and do their own "magic" to remove hidden surfaces. These additional features would be rendered at screen depth, so they appear at the wrong depth.

For a true 2D game, TVs like the Samsung (which I haven't played with) might try to "make 3D" like they do other movies/images, but it's just surface detection. For companies like Sony and Microsoft, when they talk about making existing 2D games 3D, they're usually referring to games which are already 3D, and just allowing the z-depth information to be used to display on a 3D display.