RoboDad, I believe that the movie will most likely earn more due to enthusiastic word of mouth from audiences. I’ve asked all my friends, and on a scale of 1-10, they all ranked it to infinity and beyond!
I’m impressed. Even at the rate the “Biggest IMAX in the World” is scalping Sydneysiders (At the oh-so-affordable price of just $AUD 28.50), the evening session has already sold out! The jolly green ogre doesn’t stand a chance… 
EDIT Just as I predicted, the George Street cineplex (the biggest theatre in Sydney City) booked all the VMax halls (the ones with the largest screens where they can charge a premium) for Toy Story 3. The seats for tomorrow’s screenings are already starting to fill up… 
With the midnite shows, some sold out, TS3 raked in around $41M on the first Friday here in the U.S., then $110M for the 3 day weekend, and $167M for the full week. Yesterday it pushed to $185M, and only 8 other films have managed to do this. Oh, it also made $16M in a couple days in Mexico and millions in a few other Latin American countries for a $228m Int’l take.
Like some of the posters have said, analysts had been trying to predict how well it would do, before opening day, and they had a lot of input from critics at, say, rottentomatoes. I’ve read some estimates of around $350M domestic and possibly over $900M global, which would put it into direct contact with the current champ, Shrek2. It came close to Shrek3’s opening week, but so what, everyone knows what happened to that movie, propelled by the first two of that franchise. Also, the analysts say that May tends to be front-loaded and films fade quickly, see what just happened to Robin Hood and The PofP, both films I really liked (and cost $$ to make).
So TS3 should outlast the entire summer. It’s biggest threat will be the terribly front-loaded Twilight sequel coming next weekend. It’s falloff yesterday was expected by me, since so many of us jammed to see it last week: with the huge, huge toy push here, the mag covers, the ads, the hype, and so many friends dragging others to the show. But that’s a Friday, families tend to hoard to the bijou on Sat-Sun. It came close to being beaten by the latest Adam Sandler release, but his movies never become blockbusters, and it will likely fade.
Edit:Hmm, a highly rounded $100M overseas and $227M domestic pushes total up nicely for the first 10 days. Australia came in at $6.2M on 365 screens. Remember last year when Up ruled for about 5 weeks there (with a staggered release across that continent), and finished with about $25M? Btw, Mexico’s initial 3 day haul matched each of the last 2 Pixar releases entire runs. They must have had an excellent promotion. (But I don’t think its as good as either movie)