That's not a product that actually exists. Amazon thinks there will be, but just because a placeholder like that shows up, doesn't mean there is or ever will be that product. Amazon just wants you to sign up to be notified if, IF, it ever comes out. It's not a preorder.
As for SG-1, I see it airing on the HD version of the Sci-Fi Channel all the time but not actually IN high definition. I wonder why they do that.