Of course there are all kinds of forecasts about what the Big Panda will collect in box office revenue, but we'll do a few calculations of our own ...
So if we make the (relatively) safe assumptions that quality sequels collect more revenue than the originals, we'll calculate that KFP2 will earn:
$750,000,000 - $990,000,000
I could imagine the film breaking the billion dollar mark (though given the summer competition, I don't think it's a foregone conclusion.) But I can't see it taking in much below $750 million. The Hangover is going to cannibalize a minimal number of Panda tickets, and both films will open big domestically, with KFP2 ultimately doing a multiplier of 4+ of its opening weekend.
Now we sit back and wait. And see how much of Hulett's head is buried in Hulett's large intestine.