As one might expect, he uses the Katrina disaster to underscore the point that climate change may have serious impacts on society, but he doesn't highlight the connection any more than is appropriate (see our post on this, here).
There are a few scientific errors that are important in the film. At one point Gore claims that you can see the aerosol concentrations in Antarctic ice cores change "in just two years", due to the U.S. Clean Air Act. You can't see dust and aerosols at all in Antarctic cores -- not with the naked eye -- and I'm skeptical you can definitively point to the influence of the Clean Air Act.
OK, I watched it. Its worth watching. It does a good job of describing a number of troubling developments, and risks, in an accessible way.
Unfortunately, the reaction is likely to be rooted in political assumptions. People on the left are likely to be wooed, and the film ends with a positively propagandist song by Melissa Etheridge with information about what you can do to reduce your carbon emissions interspersed with the credits. One wonders which they are more interested in getting the viewer to read.
People on the right are likely to assume that its all a bunch of bullshit. This is not helped by a few points in the film that are debatable. People who find one point to disagree with are likely to blow the whole thing off it they are so inclined. The linked article provides some balanced criticisms. I'm concerned that the Katrina implication does go too far, as the question is, at least, debated. Furthmore, I was suprised to hear him praise Chineese cafe standards, as I recall watching a PBS program on Chineese environmentalism that argued that their standards were not directly comparable to American standards and claims that they had lower emmissions were disingenuous (I can't find a good link for that now).
The fact is that these things shouldn't motivate you to toss the whole film in the bin. There are significant changes occuring in the environment, and there are real risks associated with them, and if you're not knowledgable about the subject this film offers a digestible starting point for thinking about it.
RealClimate » Al Gore’s movie