Can someone explain why DSD is exciting?

There are more aspects to DSD that are all important.   It's easy to pick on the first one and say "but that doesn't matter".
 
1. Higher sample rate - in of itself is not what makes the audio sound better.
2. Noise shaped.  It's one-bit audio, that'll sound bad if you do nothing to it, but part of the DSD process does noise shaping so you get a super low (below -120dB) noise floor in the traditional 20K audible range.
3. Signals can go over PCM 0dBFS - that makes it less important to do brick wall limiting during the mastering, and you end up with recordings with more dynamic range, or less distortion.
4. Higher processing requirements mean that the equipment is made to a higher standard, and will use better parts throughout.
and then there's PCM's dirty little secret :
All audio class PCM A/D converter chips are actually Delta-Sigma samplers with a built in a D-S to PCM converter.
The cost of the chip directly affects how complicated they make the D-S to PCM converter, and hence its quality.
By ignoring the part of the chip that is made to a price point, and grabbing the data directly at the Delta Sigma sampling point, we get a DSD stream.  Then we can use software to do the DSD to PCM conversion at whatever quality we want, even throwing the full 64 bit floating point resources of an Intel hex core i7 at it  Neither a  $1 A/D chip nor a $5 A/D chip can match this.
A DSD D/A chip similarly bypasses the internal up-sampling that goes on in a PCM chip, and drives the final output stage directly. 
 
It's a case of less is more...
 
p.s. editing at "DXD" 384kHz/24bit means you can keep the shaped noise in the signal, there's nothing audible up there - but the pre-existing shaped noise makes the conversion back to DSD sound better.
 
Tom Duffy (TASCAM)