I will be uploading a Beta of the forthcoming version 1.00 of Circle Dock in the next day or so. This will support elliptical as well as circular dock shapes.
Here's a sneak preview:
The background object is, in fact, a circular bitmap which has been 'morphed' into an elliptical shape with the same aspect ratio as the elliptical arc described by the Dock Items. Circle Dock handles this automatically for you.