From Reddit, some very plausible plot points. Read at your own risk.

Previously leaked concept art.

I love the AT AT hull being used as a base, and the burned Darth Vader mask is chilling.

Spoilers Part 1.

Spoilers Part 2.

Part 3 have been proven to be a copy cat, but still a good read, I however did not include the source.

Spoilers part 4

In part three the source stated,

In the worst case scenario, the source says he is lying to keep you interested in the film, or "muddling up other brutal rumors, hence will improve viewer experience". In an "average" case scenario, he is telling half-truths that calibrate and manipulate your expectations intelligently. In the best case scenario, he says, "I am absolutely right, but I responsibly avoid vomiting ALL of the big **** right off the bat."

Fair enough but part 3 is reported as not the source of parts 1, 2 and 4, and therefore not given validity.

On my word as an Imperial, everything I have posted here I know not to be false, yet be wary as not all may prove to be true.

TIE fighter wreckage; possibly John Boyega's

Inquisitor's lightsaber; possibly Gwendoline Christie's

Max Sydow's character examining Vader's helmet

The mighty Chewbacca

Luke's rumored location

Presumably Yavin pic 1

Presumably Yavin pic 2

Presumably Yavin pic 3

Adam Driver's character I am very skeptical of this, first its strikingly similar to Darth Revan, something I don't think the film makers would necessarily want to do, second, the new Sith characters would be among the most tightly held secrets of the production, I doubt this type of picture would be available to any but a very select few.