Gears of War 2 will be "banned" in Germany and won't release in Japan. Per standard operating procedures in these situations, the title was refused a rating in Germany, which means it cannot be sold in the country. The news isn't exactly shocking considering the original Gears of War was also verboten in Deutchland.
The Germany ban was expected, but lack of Japanese release is a little surprising. It could have been the violence was just too over-the-top for the ratings board there -- even with the game's optional gore and language filter.
Update: We're not exactly clear on the Japan situation.