The ComingSoon.net Box Office Report has been updated with studio estimates for the weekend. Click here for the full box office estimates of the top 12 films and then check back on Monday for the final figures based on actual box office.

James Cameron's Avatar (20th Century Fox) continues to be one of the biggest box office phenomenons of the decade--much like Titanic in the prior decade--having grossed $350 million after just 17 days and crossing the one billion mark worldwide. It set a new Near Year's Day weekend box office record with its estimated $68.3 million, down just 10% from Christmas weekend and making it the highest third weekend gross for a movie domestically (surpassing the $45 million made by Spider-Man in 2002).

By next weekend, Cameron's comeback will hit the $400 million mark and by next Sunday, it should pass Michael Bay's Transformers: Revenge of the Fallen to become the highest-grossing movie of 2009, as well as breaking into the Top 10 highest-grossing movies (domestically) of all time.

Internationally, Avatar has grossed $670.2 million which brings its worldwide total to $1.02 billion, making it the fourth-highest grossing movie worldwide EVER, and that's after being in theaters for only 17 days, too. It has surpassed the worldwide gross for The Dark Knight and only needs $46 million more to beat Pirates of the Caribbean: Dead Man's Chest. (Currently, Cameron's Titanic still holds the worldwide grossing record with $1.84 billion with $600 million of that domestically.)

What's so remarkable about the movie's success, besides how much of that money is being made in 3D and IMAX venues (with many daily sell-outs still being reported ), is that Avatar is also the biggest non-sequel since George Lucas' original Star Wars and Steven Spielberg's E.T.: The Extraterrestrial. By the end of January, it should have surpassed both of their non-adjusted box office takes. It's still a few days behind Christopher Nolan's The Dark Knight, which had the benefits of opening in summer, while Avatar will be facing moviegoers' return to school and work starting tomorrow, so we'll have to see whether it can cross the $533 million mark to become the second-highest grossing movie after Cameron's own Titanic.

In non-Avatar box office news, Guy Ritchie's Sherlock Holmes (Warner Bros.), starring Robert Downey Jr. and Jude Law, remained in second place with $38.4 million, but it took the biggest hit in the Top 10, dropping almost 39% from its opening Christmas weekend. It has grossed $140.6 million so far after ten days in theaters.

Also remaining in place at third, the family hit Alvin and the Chipmunks: The Squeakquel (20th Century Fox) brought in an estimated $36.6 million in its second weekend, bringing its total to $157.3 million.

Essentially, the top 7 movies remained the same with the Nancy Meyers romantic comedy It's Complicated (Universal), with Meryl Streep, Alec Baldwin and Steve Martin, staying in fourth, adding an estimated $18.7 million to its ten-day take of $59.1 million.

Sandra Bullock's hit drama The Blind Side (Warner Bros.) crossed the $200 million mark over the weekend, bringing in another $12.6 million - one of two movies that grossed more than it did over Christmas weekend.

Jason Reitman's Up in the Air (Paramount), starring George Clooney, made $11.3 million for sixth place with $45 million total. Disney's animated fantasy tale The Princess and the Frog placed seventh for the weekend with $10 million, also up over 10% from its Christmas weekend take. It has grossed over $86 million since opening in exclusive releases over Thanksgiving weekend.

The romantic comedy Did You Hear About the Morgans? (Sony) took eighth place with $5 million and $25.5 million total. (It was the only movie to move up one place.) Rob Marshall's musical Nine (Weinstein Co.) ended up at #9 (!), with $4.25 million and $14 million to date, followed by Clint Eastwood's Invictus (Warner Bros.) closing off the Top 10 with $4.1 million and $30.8 million so far.

The Top 10 grossed $209 million, up 70% from the first weekend of January last year. On top of that, it's been reported that the domestic box office amassed $10.5 billion in 2009, up nearly 10% over 2008, showing that the box office hasn't been affected by the economic crash as some may have expected.

Click here for the full box office results of the top 12 films.