This is old news. I think most people have known for a while.
It is good news though. Richard Dean Anderson is going to limit his on-screen time even more next year, and possibly not even be a main cast member any more. Plus, Amanda Tapping is pregnant in real life and consequently will also be limited, if not written out completely, of the first few episodes of the next season.
So, bringing on another big sci-fi name is a good step to filling the void.
I think Farscape enthusiasts have a mixed opinion about it. I think I've seen a few people feel like SG-1 is a step down from Farscape.
I like the idea though. Claudia Black guest starred recently and is rumored to return for future episodes (a multi-episode arc, if I remember correctly). If she were to keep coming back, maybe even become a dependable recurring character, we may see a Browder-Black reunion on SG-1 in season nine.