It does not have support for fisheye lenses, but you can download Microsoft Image Composite Editor (often referred to as Microsoft ICE) from http://bit.ly/microsoftice to stitch together photos into a spherical panorama.
If you want truly professional results, you will want a panoramic tripod head such as those manufactured by:
Nodal Ninja http://www.nodalninja.com/
You could even build your own panoramic tripod head.
The fundamental concept is that you want the entrance pupil of your camera's lens not to change altitude, latitude, or longitude in between input photos.
For more explanation, please see: