As of this morning Google has removed all wine, beer and spirits from Google Products in preparation for the transition to Google Shopping on July 1st. The policy reason has to do with a definition of alcohol as being "non-family safe": http://support.google.com/merchants/bin/answer.py?hl=en&answer=188484#US.
However this policy for Google Shopping is contradicted by Google's advertising policy for Adwords. Adwords has historically distinguished between wine and beer advertising which it permits, versus "hard alcohol" which it did not permit for a while and then allowed the promotion of drinks recipes but not the drinks. Most recently spirits product ads were permitted but required an age gate: http://support.google.com/adwordspolicy/bin/answer.py?hl=en&answer=176005&rd=3.
Given this inconsistency we are hoping their policy on alcohol will be revised once things settle down from what is a pretty significant transition. In the meantime however we recommend that stores anticipate a drop in referrals to their website which could range from 10-15%, and of course sales will be impacted.
Intriguingly, it looks like mobile searches are still showing wine and spirits searches on Google Shopping. One simple explanation is that Google hasn't updated all its servers yet. Or, as we are hoping Google Local could remain available for promoting wine, beer and spirits. We have heard that Google Local will not be commercialized like Google Shopping so we will be monitoring this closely.
You can find more information about Google's move to upgrade Google Product Search to the paid advertising Google Shopping here: http://www.google.com/ads/shopping/faq.html