While browsing around danbooru yesterday I discovered something interesting.
Volume 5. I'm...torn. Yay more SAO, but I was kind of hoping that Kirito would just have a happy end after volume 4 and they'd just introduce a new character.
What you see there is Kirito's <s>female</s> fuck if I ever trust anything I read on danbooru ever again avatar for the new game which I'm guessing is supposed to be Gun Gale Online (GGO). The new girl here is Shinon (real name Asada Shino), a sniper who uses an anti-material rifle.
I'm really hoping that the feel-good warm fuzzies from volume 4 aren't totally invalidated by this new arc.
EDIT: The title is either Phantom Bullet or Phantom Barrett (making reference to the Barrett M82). I'd bet on the latter more than the former, but who knows.