Has anyone considered the possibility that it might have been a minor Goa'uld who quickly rose to power due to the lack of major System Lords because of the Tok'ra, Humans, Rebel Jaffa, Replicators and Ori?
Just because the Lucian alliance were a major pain in the a$$ in SG-1 season 10, doesn't mean it is automatically them attacking ICARUS base.
Oh, and I knew Amanda Tapping would get a cameo. It just adds to her awesome level. I wonder what Teal'c does now? He's either gone back to Chulak or is teaching hand-to-hand combat at the SGC.