This German company called ENERCON is making large scale commercial wind turbines in the 330 KW to 5MW range.

The reason I mention this is because they have very few moving parts and they use a "annular generator", much like our little wind turbines for home use.

They also have one hell of a grid tie inverter!

They do one thing we don't do, they pitch the blades with a CPU to control speed and optimize power output.

I see no mention of a dump load so I assume they just pitch the blades in a way that they will stop in high winds or grid outages.

http://www.enercon.de/en-en/21.htm