Quoting Forget_the_Rest:

Quote:
I don't own any but I remember seeing some DVDs several years back that only had a DTS track. The Studios released two versions of the films, one with a normal DD track & a separate one with DTS.

I think even in those cases, in order to be compliant with the standard, there was generally a 2.0 DD mixdown included (which everyone ignored).  There could be exceptions, since as the format has been in place a while and I think there's less concern since virtually all modern players are DTS-capable, and folks aren't quite so intent on the compliance point for the audio.