This week (Jan 10, 2009) Avatar has over $300 million more worldwide at $1.33 billion with $430.8 domestic and $902.1 (67.7%) foreign
There was only a 29% drop in weekly box office domestically in its fourth weekend.
The staying power of Avatar suggests that it will definitely have more box office than the Dark Knight domestically and looks very good for beating Titanic domestically. The worldwide number one non-inflation adjusted box office prediction also looks assured. This should even happen within 3-5 weeks. Three weeks might look something like :
Week 5 - $240 million worldwide
Week 6 - $190 million worldwide
Week 7 - $140 million worldwide
End of week 7 - $1.9 billion worldwide.
At the end of its second weekend, Avatar had a foreign total $405 million after a drop of just 12 percent from the first weekend Avatar had earned $212.3 million after 10 days of release across the United States and Canada. The film enjoyed a surprisingly strong hold, losing just three percent of its opening-weekend audience.
I would say beating Titanic's non-inflation adjusted world total is now 100% assured.
Becoming the first film to make $2 billion is 95% certain
Making $2.2+ billion worldwide is 70%
Making $2.4+ billion worldwide is 50%
An ordinary blockbuster would have made 90% of its money by about 40 days of release, but did not get to 90% until about 120 days of release.
I think Avatar may not reach the 90% level until 60-80 days of release. The graph is only for domestic box office. It is the foreign market strength that will be the key to how huge the final worldwide box office record will be.
New foreign box office records are already being set in Korea and I would expect China. (Avatar should crush the movie 2012 which had $70 million in China) Avatar introduces a new spectacle for Imax and will set records there by being a blockbuster and a new level of visual experience.
The foreign box office breakdown at boxofficemojo shows that Avatar made $41 million in one week in China and has not opened in Italy yet.
China should have $200+ million if the first week has $41 million and Italy should have $100+ million.