Developer Rebellion has already responded, telling CVG that "we will not be releasing a sanitized or cut down version for territories where adults are not considered by their governments to be able to make their own entertainment choices."
Publisher Sega has also issued a statement of its own, vowing that "we will continue to investigate all options available to us, including the possibility of appeal." After Left 4 Dead 2 was banned in Australia, developer Valve appealed the decision. That appeal was denied, with Australia then receiving a censored edition of Left 4 Dead 2.
Such bans stem from Australia's current video game rating system, which caps out at MA15+. A R18+ rating is available for movies, but not games.
Germany apparently won't be joining in on the Aliens vs. Predator antics either, as Sega has reportedly opted to not release the game there due to ban-related concerns.
As for the rest of the world, AvP debuts on PC, PlayStation 3 and Xbox 360 in February.