It's no secret that the Sony NEX has an adapter to mount the large Alpha lenses. I guess it was just a matter of (very short) time before other adapters were available to support other lenses. The Sony NEX is very new, and it's great to see manufacturers adapting for it. Actually after a bit of research, this seems to be a one off custom job. The seller is responding to questions stating they can make an adapter for any type of lens to Sony NEX. I'm also not finding any other manufacturers of such adapters to the Sony NEX. Very cool! This Canon EF lens adapter for the Sony NEX changes alot of things for people like me who are well invested into Canon Lenses.
Just a note that someone pointed out. With adapters, they can't control the aperture on EF lenses. Your lens will default to a certain aperture and you can't easily adjust this. This seller also has a Canon FD lens adapter available too, which will give you the ability to use the FD manual lens to adjust to any aperture. The best bet is to just stick with the FD adapter and grab some FD lenses for full manual AV control.
Traveling with a lightweight camera that does both photos and videos (and awesome panoramics) that can accept some very decent lenses that I already own makes this camera much more affordable for the long run. The adapter also has a built in tripod mount, since we can't rely on that Sony NEX body to carry the weight of the big lenses. Now that's thinking smart... Check out the Canon EF Lens to Sony NEX adapter.