Wow, huge episode, lots of information, not sure where to start. As always, *SPOILERS* ahead if you aren't caught up...
So, Ellen did resurrect on the original resurrection ship right after being killed by Tigh and she resurrected with all her memories in tact. The reason that none of the Final Five knew about themselves was that Cavil (aka John) wanted them to experience humanity as humans in order to agree that humanity was worthless.
However, considering that all of their problems stem from Cavil himself, I'm not sure his plan will succeed.
Due to the bullet in his brain, Anders remembers everything as well and fills the other four in as much as he can before his surgery.
A few of the main things I found interesting from this episode,
1. The Centurions came upon the idea of the One True God on their own and Ellen used it in the programming of the skinjobs. It even appears that Ellen has come to believe in the One True God herself. I would assume that the humans who created the Centurions wouldn't have programmed them with religious thoughts (and if they did, they would have used their gods) so this is something they came up with own their own when they became sentient. Very interesting.
2. Number 7. I've always thought it was strange that there wasn't a Number 7. I hypothesized that maybe that meant the Boomer/Athena model (number 8) was tied to the final 5 in some way, but instead it turns out that the Final 5 in fact created 8 models and number 7 has been boxed, supposedly even more completely and permanently then number 3 was, however somehow I doubt that. The question clearly is who is number 7? There are really only two possible answers in my mind, either Starbuck (which would be possible, because it reappearing as a female would answer why no one recognizes it, and it being Starbuck would answer her resurrection, plus there is the fact that 7 was an artist and Starbuck kept painting the eye of jupiter) or Baltar (which is what I'm leaning towards because Anders talked about seeing someone no one else could see, he saw a woman, Tory saw a man, very similar to the 6 that Baltar sees and interacts with and the Baltar that 6 sees and interacts with).
3. Galactica will become alive. I'm very interested to see what ramifications this will have on everyone's relationship with her. Especially considering how important the ships are to everyone's identity. Lee's new Quorum uses ships for the representatives instead of the now extinct colonies. The other thing is, while the ship is getting fixed, it can't jump, but with Ellen finding them from Cavil's group, whose to say Cavil won't find them too before Galactica is ready to jump away?
Until Next Time, This season is everything I had hoped for so far and I can't wait to get more answers and see what will happen next!