This short assemblage of Paranormal Activity 4 footage is being called a "viral clip." I think it's the most interesting bit of promotion for the film so far as it seems to sell a couple of fresh ideas.
So, there's the idea about "it" coming for kids. And the "it", I'm thinking, is Katie from the first film. Certainly looks like her.
And then there's the automated system announcing breaches of the house's security – "Back door open, front door open" and so on. I'm hoping that's put to creative use.
Then we shouldn't overlook the allusions to the illuminati in the title card.
I'm rooting for this one. Thanks to Digital Spy for the embed.