I disagree. Killing off Stargate Atlantic and replacing it with Stargate Universe was the beginning of the end.
What's really sad is that their highest rated show is a wresting show, which shouldn't even be on that channel.
There's still some good shows like Eureka and Warehouse 13. Eureka is ending though.
I miss the original Scifi Channel with reruns of old shows and a show called SF Vortex that usually had Harlan Ellison and some other hard core Scifi folks commenting on the current state of Scifi.