A lot of the urban imagery is not satellites but is from regular aerial photo surveys taken frequently over US cities by USGS. This is why there is a discontinuity in the resolution of the images as you zoom out or move away from cities. Aerial photos are taken at fairly high shutter speeds, which would mean a wide lens aperture, but still, the depth of field is sufficient that an object would not be blurred unless it was really close to the airplane. Maybe a water droplet? The other images at...
wsanders: Comments
Same location on Microsoft Maps, nothing unusual there:
http://terraserver.microsoft.com/image.aspx?T=1&S=10&Z=17&X=2960&Y=14794&W=3&qs=%7cWest+Palm+Beach%7cFL%7c