I can't take the credit, or the blame, for noticing the resemblance. That goes to Caitlin McDevitt at Slate's The Big Money, who light-heartedly suggests it "may be more than a coincidence."
She asks, "Could someone at Pixar be equating Buffett's predictions to a lot of hot air?"
Perhaps the usually "grounded" Buffett will become unhinged by the economy's troubles, sending him "spiraling uncharacteristically out of control."
One key difference: Carl's creators describe him as a "grouchy old man" while Buffett always seems to have a smile on his face.
They say Carl is physically modeled, at least partially, on the actor Ed Asner, who provides the voice of the character.
Other cited influences: the late actors Walter Matthau and Spencer Tracy.
You be the judge.