Canon's new 8-15mm fisheye zoom.
That' some weird looking reflection in the glass!
When paired with Canon’s full-frame DSLR bodies, such as the EOS 5D Mark II or the EOS -1Ds Mark III, professional photographers can choose to capture circular or full-frame fisheye images, allowing them to view a scene in a completely new and unique way. This new level of choice provides enhanced creative flexibility when shooting scenes such as the night sky, where the full 180º horizontal and vertical fields of view (FOV) allow every detail to be captured with incredible clarity in one single image.
When used with EOS bodies featuring APS-C or APS-H sensors, the EF 8-15mm f/4L Fisheye USM produces a more traditional, full frame fisheye view. A zoom-lock mechanism on the lens body allows the range to be limited to the focal length that ensures the best possible full-frame view without unsightly vignetting around the edge. ‘C’ and ‘H’ markings can be found next to the zoom operation ring, indicating the wide-angle zoom position where vignette-free shooting is possible with either sensor, allowing photographers to achieve optimum results with any EOS body.
I'd be tempted to buy one, except that I already have an inexpensive Vivitar 7mm fisheye lens ($360) which, while it's not a Canon L job, works well for occasional pieces (and let's face it, you don't use a fisheye lens all the time anyway!)
I'm under the impression that the Vivitar lens is actually produced by another company and sold by a couple of vendors - I've seen it described as both a 7mm and an 8mm lens. Here's a short sample that will give you an idea of what the Canon lens will probably look like at 8mm on a Canon APS-C sensor camera:
B & H: Vivitar 7mm f/3.5 Series 1 Fisheye Manual Focus Lens
Canon: Zooming Fisheye This page contains a video that shows the zoom effect on a Canon 5D Mark II (i.e. full frame camera; the effect will be different on an APS-C camera.)
B & H: Canon EF 8-15mm f/4L Fisheye USM Fisheye Ultra-Wide Zoom Lens (Notify when in stock) ]