A new scan from Shonen Jump magazine confirms the 8-Tail Jinchuuriki himself, Killer Bee, as a playable character in Naruto Shippuden: Ultimate Ninja Storm 2! Looking at the scan, it seems like Bee’s awakening mode is taking the form of the 8-Tails! Kind of like 4-Tail Naruto!
It could also be assumed that Bee is a boss, however, the scan does not confirm this as his character icon is on the left side and is smaller. Take a look at the Itachi boss battle scan and Orochimaru boss battle scan. Both of those feature the boss character icons on the right and are larger-than-normal.