Not clicking on that link as I don't want to go in knowing too much (didn't I say I was gonna stay out of this thread entirely?), but I do recall the early rumors saying something about the third act having a huge "I am your father" level twist/reveal.
The overall sentiment I've been getting from those in-the-know has been that TFA is most similar to ANH tonally but has a very cliffhanger-y, Empire style ending.