Project Soul's Hisaharu Tago just announced tonight at Namco Bandai's Level Up event that Soul Calibur 5 is indeed very real and currently under development, all the while brandishing a sword on stage.
According to Tago, the battle system has been improved quite a bit with plenty of new features added. In addition, the main character for Soul Calibur 5 is apparently called Patroklos.
"The tale of Patroklos, son of Sophitia Alexandra, unfolds as his family's destiny intertwines with the Soul swords. With the series revolutionary 8-way run, allowing for true 3D movement during matches, a refined battle system, and stunning graphics, Soul Calibur V will be the top game of 2012 for anyone looking for a knock-down, drag-out fight."
The game is scheduled for release next year, likely on both PS3 and Xbox 360. Expect more info on the game at E3.
Kudos to VG247 for the image.