A quick summary I wrote on the fly.
In this episode we finally see Homura's story.
It's revealed that Homura wished for a new meeting where she would be the one protecting Madoka, and not vice-versa.
Homura keeps switching to alternate dimensions everytime she fails to protect Madoka after the Walpurgis Night.
It's also funny to see how characters act differently and going all angsty in one dimension (rip off Bokurano much?).
The episode ends with Madoka making a contract with QB and defeating Walpurgis Night. She transform into the strongest witch. QB confirms that they have gathered the necessary energy and says that mankind has to deal with Madoka who turned into a witch.
Homura walks into another dimension (iirc episode 2) and the episode ends.