I didn't see this post at this forum. So more information you can find here!
I ordered an adaptor on 16:9.net and don't buy the new Canon 14mm but instead the Nikon 14-24mm F2.8
is a seller on ebay who may be the manufacturer of these adapters. I own three of his adapters. (Pentax, Nikon and Olympus) They work pretty well and cost between 50 to seventy bucks.