The b.yond has no S-Video out. If you need to use S-Video, you have to find for a device that converts component video to S-Video.
Something like this: http://www.svideo.com/appletv2tv.html

It's not cheap tho. I think better idea to change TVs to use component if you emphasize quality.

Well, you can still go for b.yond, if you can find that component to S-Video converter. Look into Pasar Road, maybe they have converter at cheaper price.

Of course, understand that even using this way, you can only get HD on the main TV (which need to have HDMI connector), the one in the same room with the b.yond. All other TVs will receive SD picture.