Soundgarden = wildly creative band, and always interesting, even if some of their experiments were hard to listen to.
Audioslave/Rage Against the Machine = some of the least creative, boring, overrated music created by great musicians who should know better. If I hear Tom Morrello do one more cliche pentatonic Black Sabbath riff, and then step on his whammy pedal to do his standard "whicky whicky whicky" solo I'm going to punch myself a fanboy.
As for Chris Cornell leaving Audioslave, I'd love to see Soundgarden get back together. Perhaps if Rage reunites and then learns how to expand upon their rather tired sound, I'll give it a chance.