I didn't fully understand the whole plot with The Maestro, and it just seemed to be played as a fun episode (save for that scary alternative present in one scene), and once again it became "Doctor Who the Musical" at the end with that song. Entertaining, but hard to understand.
I wondered if William Hartnell (well, David Bradley anyway) would make an appearance, but the mention of the original Doctor seemed to be just a throwaway moment. The revelation that the Toymaker is the Maestro's father made sense, particularly with the harkening back to The Giggle (probably not the last).
I'm noticing snow becoming a recurring theme this series; I'm guessing it will keep on appearing, as it seems to be linked so heavily to Ruby Sunday and her backstory.
I can't wait to find out who "The One Who Waits" is; could be a subtle way of bringing back a character like Bill or Amy Pond, who were both well known for waiting for the Doctor (Amy would have been around somewhere in 1963, with Rory). However, this is probably the "boss", who the Meep mentioned before.