Japanese demo for Ninja Blade would feature both region-free access and English text, we never thought that these elements would carry through to the final build. Nope, never saw that one coming. Well, it did; the Asian retail version features English language options (among a slew of others) and it's region-free, making it also import-friendly.
Without a confirmed release date for North America, importing Ninja Blade seems like a rather tempting option if you find yourself looking for more ninja action on the 360. It's also 10 bucks cheaper than what you'd get locally.