I've never heard before about the x.v.Color space and after Googeling a bit I found plenty of information about:
xvYCC - Wikipedia, the free encyclopedia
Color space - Wikipedia, the free encyclopedia
Sony Global - Technology - xvYCC

As I understand this standard makes legal what was considered illegal in Digital Video: Y'CbCr values below 16 and above 239.
So even MiniDV is able to record x.v.Color.
Just to be careful on how to process (applications, codecs, interfaces, delivery formats..) this signal, otherwise those values will be clipped. Think as well that certain monitors won't be able to display this "extended gamut".
rafael
PS: A new (2.005) name for something old.

In reality, the x.v color does not seem to be a big deal at all, but my nanoflash is!! I can say that now!