It almost seems as if the release of this fisheye is targeted towards both crop and FF camera bodies, which seems like a winner in my book, compared to producing separate fisheye lens for crop and FF bodies like other competitors are doing. While the $1400 price seems kinda high for this fisheye (given also that it's a non 2.8 or IS lens), I'd say a more reasonable price range is around $999-1299 comparing it to the older 15mm and other niche performance lenses Canon offers.
Edit: http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=3507
As mentioned there "The ability for one lens to handle multiple fisheye tasks, which previously required two specialized and expensive lenses, has remarkable potential. A magazine or commercial shooter who works with full-frame cameras now has at his or her fingertips a single lens that can handle both full-frame fisheye and true circular fisheye tasks. Likewise, a photographer who may own multiple EOS camera bodies — for example, an EOS 5D Mark II and an EOS 7D — can now achieve the full-frame fisheye effect with both cameras. A photographer no longer has to choose between, say, the speed of an EOS-1D Mark IV and the full-frame sensor of an EOS-1Ds when a full-frame fisheye image is needed, because the new EF 8–15mm f/2.8L USM gives that option on either camera."
I am going to assume based off the page's explanation for FF users, the options of use would either be a 15mm rectangular fisheye or an 8mm circuluar fisheye?