You'll be able to alter the language of your Xbox 360 from the dashboard - not the region, mind, so there's no sneaky-importing-of-games-from-other-territories - but you can choose one of the supported languages no matter where your Xbox is. If the game supports translated speech and/or subtitles, it will use them, so yes: you can play Kameo in English wherever you are if you so desire.
The Kameo localisation teams were given full access to builds of the game, design resources, my speech resources and expert assistance from our programmers to create the best translations possible; in addition, some of the localised versions have big-name voice talent. As Mr. Munson mentioned, Romi Paku (Edward in Full Metal Alchemist) is lending her significant talents towards voicing our Japanese Kameo...