I've been away for a while and so not been contributing but this thread has really got me! I think Pushkin is essentially right in that we mustn't abuse our bodies if we are looking for health; however, there is nothing per se wrong with cocoa (organic, no refined sugar) nor with soy/rice milk, but the habitual use of sweetened cocoa with dairy will get you in trouble. (Soy may cause different problems but rice milk is probably ok).
I remember once reading BKS Iyengar (the great yoga teacher) saying that coffee in itself is not harmful (sorry not exact words, just the gist of what he said) -- it's just afterall the juice of the roasted coffee bean, but the habitual use and abuse of drinking coffee is the problem. Everything in moderation.
Didn't the Mayans and Aztecs drink bitter chocolate? Now, did they drink it for real energy or just for the buzz?