Oh course... SPOILERS!
1. The scientist (please someone give me the full explanation who she is) at the beginning of the episode with 4th Doctor's famous over flowing scarf. They length of which ends up saving her life.
2. The return of the fez. I mean, bow ties are cool... but fezzes? Well they're fezzes.
3. Rose/The Moment/The Interface mentioning Bad Wolf. I mean well... tears.