I've really enjoyed yesterdays episode. Overall the story telling has been great this season. I'm still afraid they might blow it up in the end and do something stupid as they did so many times in the past.
But I keep wondering about a few things... why are the angels working for the division? Have they created the angels? What do they have on them? Do they even need them, are the angels collecting time energy for them to allow for time travel? I thought the TARDIS is powered by a replica of the Eye of Harmony, so no need for time energy?
As for the doctor... are Bel and Vinder the Doctors parents (Bel is pregnant)? Will they go back to the planet Time where the Doctor will be born (outside of time and space)? Will the energy collected by the angels be important to the birth of the Doctor and therefore make him/her what he/she is?
At the very least I expect more information on the fugitive Doctor and maybe memories returned from before they were erased by the division. If we get additional answers to the question in spoilers above, even better. If not, there should be plenty of material for future seasons.