I doubt it, not that the 360 needs saving in Japan. It is not doing well but there is enough of a war chest behind it to make sure it is always there.
However Ace Combat is likely to shift a whole pile of consoles since Microsoft paid out to get the Capcom exclusivity. Most of the world is ignoring the upcoming Ace Combat release due to Halo 3, but the Japanese have never really been into the fast paced FPS style games.
Prolly Not: Can Ace Combat 6 Save Xbox 360 in Japan? – Kotaku
Last Updated: September 7, 2007