I can understand how you feel due to the abrupt ending, but what made it such an impressive book was how they captured the survival-horror elements of the
Aliens franchise. Instead of following the formula of Cameron's film, they really followed the formula of Scott's film while tying it into the setting of
Prometheus. I also do not think that they are going to leave the
Aliens book in the dark. There are too many loose ends that were not explored in the other books.
Spoiler
A perfect example is the queen. I am going to assume that Ahab, Angela, and Galgo are going to have to face her. Also, let us not forget about the Deacons. What would be really cool is if the Deacons and the xenos have some kind of hive war going on like in Genocide with our respective protagonists in the mix.