Some of it, as in most Moore films, is really very well done. The best example of this is when Moore asks various financial experts to explain what a "derivative" is. In each case it is so complicated, they cannot! Very telling, and very disturbing.
The most interesting thing about this film is Moore's use of his own Catholic faith to attack Capitalism. Catholic economic justice runs strongly counter to our culture of greed and cut throat competition. And it is nice to hear this said. It is also nice to hear from the religious left. Too often religious messages in the media and film are right wing.
In a particularly telling and funny scene Moore dubs over an old movie about Jesus. He has Jesus mouth capitalist catch phrases, and the result is quite damning. It's impossible to imagine the Jesus of the gospels saying such things or even approving of anything like our own economic system.
I highly recommend anyone interested in the social justice aspect of Jesus' life and teaching to read Jesus a Revolutionary Biography by John Dominic Crossan. Once you have studied the figure in his historical environment, you will see that Moore has the social justice and anti-capitalism of Jesus and much Christian social justice teachings absolutely correct.
Of course the usual superficiality and pompousness of Michael Moore does hurt the film. But I think the film is worth seeing, and much of the message is well presented and substantially correct.
But if you don't have time to see Moore's film here is his October interview with Charlie Rose that pretty much sums it up: