That would be because I have seen this demo in person. Also that is not the only TV that supports 10-bit color. The pioneer line of plasmas supports it. The FHD-1 which is there 50" 1080P set has been out for a year now and supports it, as does there less expensive ones.

Now, even if there were no tvs that support it right now.....but there are......there would have been in the near future and the PS3 is set up for this. Sony thought ahead a great deal with the PS3. They dont have a perfect console yet, but who does.......noone.

This is a link to an AV forum that breifly explains the difference between HDMI1.3 and other formats. Although the picture doesnt show a real representation, in person it is very noticable. The PS3 having used HDMI 1.3a will have full use of 10-bit color. No other format will allow for this.

http://blog.ultimateavmag.com/ces2007/010807HDMI/