We have no plans to change the ship speeds on the open sea. They're as fast as we can make them without being too fast.
A word on simulation:
We're clearly not a historical simulation. We started on that path, built that game, and boy, did it not work. Yes, yes, I know there are people who think that would be a great idea, and for a very small group of people, it would be. But as a commercial venture, not so great.
What we try to do is be true to the setting. Which means while our ships don't move at accurate speeds, or actually stop and move backwards when going into the wind, they move at speeds that reflect their traditional role, and evoke what it was to sail those ships.