I have to agree with some of the comments about using a faster shutter speed to slow the spinning motion and to show the blades more. I think it is a very intersting idea and the colors are very nice and bold. I'm just missing seeing more of the blades in motion. As it is the pinwheel tends to look a little small in the frame but maybe would not if the blades were not quite so blurred.
The composition is pretty good with the pinwheel set to the right of center. I may have preferred to see it positioned at a slight angle, leaning outward, to provide a more unbalanced feel that I think would match nicely with the spinning motion. It is a simple composition and I like that aspect. Someone mentioned showing many pinwheels in motion and I think that would have been an interesting idea as well, almost like a field of daisies.
I like the slight blur to the stick as it blends in nicely with the motion blur. It helps to increase the feeling that the pinwheel is somehow being transformed or disappearing into the background. It is appropriately sharp in the center of the pinwheel where it should be. This provides a solid starting point for the eyes to rest before viewing the rest of the image.
This photo clearly meats the challenge, it is an interesting and unique idea, and you executed it nicely. Good job.
Great photo, very original and well composed. You have captured this one excellently, I can almost feel the breeze coming off the monitor into my face! Good job!