In its original state, Fallout 3 was deemed no good for the Australian market. Too many drug references for the Australian Office of Film & Literature Classification's liking. But now, well, now it's all good! A revised edition of the game has been cleared for release, and has been classified MA15+ by the OFLC, a rating based on the title's "Strong violence, drug references and coarse language". For the record, an MA15+ rating - the highest Australian law permits - means persons under the age of 15 can't legally purchase the game. What's unknown at this stage is the extent of the edits made; it could be a few simple name changes to the in-game drugs, it could mean a more fundamental overhaul of the game's menu/icon system, we don't know yet. It's the middle of the night in Australia. We'll update when we do know.
UPDATE - We contacted Bethesda to ask what had been edited/cut and - just like Rockstar with GTAIV - they could/would not comment on the changes.