Decanter BioDynamic poll
But what we can say is that the majority of responses look unfavorably on the label of BioD on their wines:
If we extrapolate the "don't know" response proportionally to the other two categories it appears to be roughly a 60:40 split against BioD, which is what I remember the margin to be against Sonoma County's failed Measure M, the anti-genetically-modified-organism proposition from last year. (The two subjects aren't necessarily related, but I just thought the similar numbers were interesting.)
The best news is that it seems to show that the plain majority are skeptical of the effects of BioD on the final wine, so there may be hope for humanity yet.