Yeah, I can see that (and also remember the ep because, yeah, we're geeky that way!), my thing with it is that in order for time travel to be possible at all, and in fact Castiel says so himself, is if time is something fluid, relative, in which case past and future aren't really so and if you get philosophical enough it could even be argued they don't exist. The reason why I can't really go for that is that if it is indeed predestined because it happened, then why couldn't Castiel send Dean as a mere spectator, though if it is as you say, then DEAN himself was meant to step in and affect things, which would bring a nice shade to Castiel's possible motivations (be them individual or part of a bigger plan)... that does look good, but still I struggle with theoretical conceptions and really, I watch Dr Who, you'd think I'd been cured from this, but there ya go!

VULNERABLE! OMG that's the word! It's not that she can't act, because she can, I just think she doesn't really know where the writers are taking Ruby (remember the whole Jo thing, where Alona didn't know for sure what was to become of Jo because no one had told her and so she played her one way and then when new scripts arrived she had to change that to accommodate them?) and so all she has to work with is Sam's reticency to let Dean know what he's been up to and the fact that Ruby seems scared of angels... maybe later on she'll grow into the character and Ruby's, uh, Rubyness will come back? ::hopes really hard::