Is it fake?

Bit of an impromptu post this one, brought about by the leak of what is alleged to be the 6th Edition 40k rule book. I haven't seen this document myself as I wouldn't know where to start - law-abiding citizen that I am - but I've kept an eye on scuttlebutt on various forums.

So what do people think? Is it real? Is it an elaborate fake? Or is it, as is likely, an early playtest copy?