The current DNG 1.2 specification is sufficiently rich to represent (and allow decoding of) raw data for the vast majority of the cameras that shoot raw. (The exception is Foveon.) The specification does contain a chapter presenting a baseline scene-referred processing model, i.e., how to get from camera-native coordinates to RIMM.
However, as I've indicated earlier in the thread, and elsewhere, DNG is not intended to universalize or standardize output-referred rendering (whether display-referred or print-referred, the two most common options). There is little point in standardizing scene-to-output rendering controls commonly found in raw conversion software and given common labels such as contrast, saturation, presence, clarity, boost, etc. Just like there is little point in standardizing the print-referred perceptual tables that go into ICC printer profiles; it is up to each profile-creation software (e.g., ProfileMaker, MonacoPROFILER, Argyll, etc.) to make its own decisions/tradeoffs about the rendering, but ultimately they stuff the secret sauce into a common container, i.e., the BtoA0 tag in an ICC profile.
That said, the DNG specification does allow camera makers to include a desired default "appearance" or "style" if they wish to (I have demonstrated this with the Camera Matching beta profiles, and Casio will demonstrate it with the EX-FH20, which has full support for DNG 1.2 extended color profile format, and two other unnamed camera makers will follow suit in 2009 and 2010.)
I should also mention that many photographers are under the (mistaken) impression that Adobe just cranks away on DNG on its own without consulting the camera makers, then simply expects the camera makers to "catch up" and "get on board" whenever Adobe releases an updated DNG spec. If that were true, then I could sympathize with the perception that Adobe is being arrogant with respect to "dictating" the format for the industry. However, that is not the case. We consult with most of the camera makers regarding future plans/updates for DNG, and some of the changes & additions made to the previous 2 DNG spec updates (1.1 and 1.2) were the direct result of constructive feedback from these camera makers. There are some encouraging signs that this collaboration will expand in 2009.