I think most of us saw the Barriss revelation coming earlier in the arc. The strange thing is her motivation: she makes it sound like some sort of highly-principled act of defiance against the corruption of the Republic and the Jedi Order for serving such a corrupt body. She is shown meditating in front of some sort of Buddha-like statue in her room, and later she decries how violent the Jedi have become by participating in the war. Her actions, on the other hand, say "I'm dark side now, twiddle-dee-hee! I blow up hangers full of innocent people and frame my best friends for murder. Oh, and red lightsabers really complement my eyes, don't you think?" It doesn't really add up to anything coherent, and that's my biggest critique of an otherwise excellent episode. I realize this show was really about Ahsoka and not Barriss, but they could have at least come up with something consistent for her. If the intent here was to give Barriss a legitimate point to make about the current state of the Jedi, then it's really undermined by everything else she says and does. Well, I guess Ahsoka should have taken the opportunity to whack her in "Brain Invaders" after all, eh?