Not directly related to SpaceX, but pretty exciting news, it could really open up the solar system (thus makes Mars colonization easier, so not totally unrelated to SpaceX ;-) ). This drive is similar in effect to EMDrive, but is much less controversial and has much better theoretical foundation, it's also less well-known. To see a layman's explanation of this drive, see: https://boingboing.net/2014/11/24/the-quest-for-a-reactionless-s.html, there's also a book: Making Starships and Stargates: The Science of Interstellar Transport and Absurdly Benign Wormholes
NIAC is NASA Innovative Advanced Concepts, it's a program to provide small amount of funding for TRL 1 breakthrough technologies, this is the best part of NASA IMHO, really what NASA should be doing.
I don't know what peer-reviewed papers have been published, but Woodward recently published a book.