It looks like any hopes Xbox 360 owners may have regarding seeing Ninja Gaiden Sigma ported over from the PlayStation 3 have but all been dashed. Talking with Japan's Famitsu Xbox 360, Tomonobu Itagaki had this to say about the whole deal:
"We're getting requests to port Sigma to the Xbox 360, but we currently have no such plans. But no worries, 360 owners! Team Ninja is still supporting your platform.We're taking new challenges on the Nintendo DS, and the same is true for the Xbox 360. In order to respond to our fans' expectations, we're always making sequels and new games."