Additionally, Japanese site My Game Flash has rounded up other complaints about the localization, most notably an alteration to the sensationalized "No Russian" mission. Rather than delete the mission (as in the censored Russian version), Square Enix had the Japanese version of the mission adjusted to restrict the player from participating in a terrorist assault on an airport. If the player does engage civilian targets, it's game over.
Square Enix has posted an update on the Modern Warfare 2 Japanese site describing the full Japanese language and subtitle tracks and warning of the "No Russian" edits, but has not announced plans to patch the translation errors or change the limitations on the censored mission. The publisher has cited technical limitations, which prevent selectable English and Japanese language tracks. Head past the break to see some footage of the Japanese version of MW2, courtesy of andriasang.
Source - My Game Flash [machine translation]
Source - Famitsu [machine translation]
Source - Modern Warfare 2 Japanese site