When the first protester throws the egg at Harold's assistant, we see on the far left a woman wearing a red scarf and a woman next to her wearing a multicolored scarf. In the shot just before this the woman wearing the red scarf has vanished, and the woman with the multicolored scarf who didn't have a big white sign in her hands, now does.
Santa Claus has left his bloodied hat near Harold's fireplace when delivering his tree. However, in the final scene of Santa Claus (and the movie), he can be seen wearing the hat.
When Todd walks in on the party guests doing cocaine, he is holding Ava facing him. When one of the guests sneezes the cocaine toward Todd, Ava is now facing the party guests.
Yes there is, after the credits you see NPH stand up and walk away.
Q
What are the differences between the Theatrical Version and the Extended Cut?
A
The Extended Cut, which has been released as a Blu-ray exclusive, features 1 additional and 12 extended scenes for a total of more than six and a half minutes of new footage. Besides some extended dialogues one can also find some more nudity and violence and some more jokes about religion and politics. A detailed comparison between both versions with pictures can be found here.
Q
Didn't Neil Patrick Harris die in the last film?
A
Yes. In this film, it explains that he went to heaven but Jesus got his dad to send him back to Earth for stealing his women and also after the credits of the second film he stands up.