That is the screaming headline of this Bloomberg piece, and if true that's really amazing. I guess I need to read up more on how exactly that is supposed to happen: this short piece doesn't have a lot of details....
Update October 7: one of the reasons is economies of scale, and another reason is improvements in technology such that they turn in even really low wind. I know very little about this technology, but I am curious about how it stands up to extreme conditions. I'm sure the engineers have thought of that, but can they really?
Update October 25: Another recent report has highlighted the vast potential of offshore wind. Unfortunately this doesn't say why costs are dropping so drastically, but they say that as much as $1 trillion could be invested in projects by 2040. That would be... a lot!