Mary Baker from Dover Canyon pointed me to this discussion, Worst Winery web sites??? at eRobertParker.com where a variety of "oenophiles" take winery web sites to task. I'm not one for piling on, so you can take a look for yourself if you're interested in specific names.
The consistent complaint for all the wineries mentioned in the discussion, however, is that their Web site isn't helping the visitor achieve the goal they came with (whether it's ordering wine, getting a picture of the label, or finding contact information). It really is all about visitor effectiveness.