I've thought some more about this, and I have another thought to add.
I think that the "finding home" plot is central. I think it is NECESSARY for an animated film to be a financial success. - over 100 million. I do not think it is necessarily SUFFICIENT though.
I think there are several other factors that can account for the variance in animated box office - these are not necessary or sufficient for success, but can explain some portion of individual differences from film to film. In other words, you can think of them as adding bonus points or taking away points from a film.
Among these are:
The visual appeal of the animation (the cgi vs. traditional animation factor is actually here; right now cgi is fashionable)
music
celebrity voices
animals
princesses
funny sidekicks
franchise / built in audience
reputation of studio
quality and quantity of commercials / trailors
promotional tie-ins / plush
lack of something lame (like flying boats or talking vegitables)
amount of competition at release
None of these factors can ensure the success of a film, particularly if it misses the basic plot.
Here are my predictions for upcoming movies based on these theoretical criteria:
Brother Bear:
Orphan finds home, learns lesson along way.
Bonus points for: quality animation (only 1/2 points), music, animals, funny sidekicks, promotion and plush, studio, celebrity voices.
My guess: 200 million
Shrek 2:
Not sure about plot, assume it will have basic necessity.
bonus points for: animation, franchise, studio, promotion, funny sidekicks, animals, princesses, celebrity voices. Looses points for amount of competition (Spiderman 2, Potter 3).
My guess: 250 million
Sharkslayer:
I don't know if it will have plot necessary.
Bonus points for animation, studio, promotion, animals, celebrity voices (Will Smith, Gandolfini). Has a potential negative in lameness, depending on how they pull it off.
My guess: 100 million
Kim Possible:
I don't know, but I don't think it will have plot necessary.
Bonus points for animation (1/2), franchise, studio
My guess: 34 million
Over the Hedge:
I don't think it has plot. Not sure.
Bonus points for studio, animals, maybe for animation, not sure.
My guess: 60 million
Wallace and Grommit: great vegetable plot
I don't know plot.
Bonus points for franchise, studio
My guess: 70 million
Incredibles:
Assuming plot has necessary elements; I think this will come in terms of finding lost youth
Bonus points for animation, studio, promotion, tie ins, celebrity voices
My guess: 250 million
Madagascar:
it sounds like it will have the necessary plot
bonus points for animation, studio, promotion, celebrity voices, animals
My guess: 150-250 million, I don't know enough about it to pinpoint yet
Cars, chicken little, snow queen, robots:
I don't know enough about this to guess