SACD or DVD Audio, which one is winning the race?

The stereo program on SACDs is an AREA of the disc, not a layer. The layer idea (Hybrid SACD only) relates to a media that can be read by regular CD players.

At present a DVD-A disc does not have a stereo program although
(1) the player can do a realtime mixdown
(2) I heard a rumor that the DVD-A spec was being revised to provide for a stereo program.

Sorry about that, I meant "high definition" in a general sense; a better term would have been "the more detailed, the better." What I was driving at was like comparing the level of detail between an MP3's and the ordinary CD's: we all know the level of detail is different simply because there are larger number of bits in the latter and so isn't it reasonable to say that since there are more capacity on the DVD, it can be made to have a higher level of detail (or bits) on it than on the CD for the same lenght of music? Or am I too naive (I'll have to admit I'm ignorant on technical matters)?

Emafaith: I think you're confusing "detail" and "resolution." The latter is the technical term, and is directly a function of the number of bits. The former is a much more subjective term, used by reviewers and audiophiles to describe how well a system allows a listener to pick out particular, subtle aspects of the music, e.g., individual instruments, etc. (Others may well have different--and quite possibly better--definitions of the term.)

You can have great detail without great resolution. LPs, for example, have much lower resolution than CDs, for example, but a many a vinylphile can tell you about the detail of his rig.

Thanks, that was clear enough, but I'm quite surprised, I mean really surprised to know that a lesser resolution format can give more detail than a higher one; It just seems to defy logic, although I'm certainly not arguing the point especially where it is accepted by many audiophiles. But my common sense tells me there are some deficiencies in CD format as it stands now if its higher resolution system can't extract more details than the lesser resolution LP's. I simply can't think of any other reason why it is so.

Emafaith: I never said that CD can't "extract more details" than LP. Because of differences in dynamic range (which is directly related to resolution), a CD can capture some details that an LP just can't.

Now, whether you can HEAR those details or not depends on the rest of your rig, particularly your speakers and your room set-up: That's where details get muddied.