This was a great episode. Funny, perfectly paced, reinvented the Daleks, gave Smith even more choice time to show his stuff, and a WWII dogfight in space. It was also entirely unexpected, given the heavy emphasis on the Daleks' deception in the advertising.
I disagree the best two parter of the current run was Lost Earth and Journey's End both Dalek episodes. I saw the first Matt Smith episode. The crack in time is interesting as well as the new Tardis, the rest is just there. Loved the Dr.Who through the years montage.
It's not much of a joke. A family walks into a talent agent's office and says they've got a great idea for an act. The agent says he doesn't book family acts, but they persuade him to take a look at theirs.