Interesting book has appeared on Amazon.com...

If I recall correctly many moons ago, a book deal was given to explore the events prior to Covenant. 

Since this book isn't coming out until September 2017, it's probably the novelization for the sequel/prequel Awakening, which Sir Ridley is trying to get made ASAP. 

I remember lots of vague talk, but I wonder if this is going to be one based on another upcoming movie or a stand alone novel.

It will be a prequel story by Alan Dean Foster. The official novelization will come on 23 May from Alan Dean Foster too. On Foster's official webpage the prequel book called Alien: Origin. As he said, itt will be an original and official story from him and not a movie novelization.

Ty metalos that explains that!