They haven't formally announced yet, but it's imminent. They would be a Science Fiction, Fantasy and Alternate History channel with all-original programming, to start delivering content in 2010. It's all contingent on financing, which would eventually depend on a subscription model.
Their site includes a BBS where you could ask questions and find out more, but there will be a chat (IRC) at their site at 4 PM (U.S. Eastern Time) today, and at various times in the future. There are Chat and BBS links on their home page, and even an IRC client.
Start-up financing is contingent on interest. Also, this is largely run by fans dissatisfied by existing SF offerings, and they are very receptive to feedback and suggestions. I hope this will become of particular interest to filkers, but if you read SF or watch SF movies, I suggest checking this out. Making your interest visible would be even better.