Only downsides to wind that I know of is it can cause erosion on banks, it can drop temps really fast in a small pond and stress fish, and of course if you have an anoxic layer on the bottom of your pond it could bring it up and cause a fish kill. But that is perventable if you use diffusion to break up the stratification.
I could also have some problems in my trout pond if it is excessively hot with high winds (very rare here).
Overall though, as Bruce has stated wind is a good thing. I'll take wind action over stagnation any day. My ponds get a lot of wind too due to alot of treeless open farm land and other open land around me.
To show you how quickly temps can rise in a pond with high winds and warm temps last spring I had my big pond go from near freezing (it has some ice the day before) to 50 F. in one day from top to bottom. Surprized me! The winds were gusting into the 40 mph range and temps were in the 70's. This is a 3/4 acre pond that averages 7 feet deep.
