Haven't seen the movie, and don't really plan to. Michael Moore isn't exactly the guy to go to for a completely accurate documentary. I did read one review that made some quite good points - while Moore does a good job of pointing out problems in our system (though often cherry picked exceptional cases rather than general ones) he doesn't give any problems that happen in countries with universal health care. Take for instance that in Canada dogs can get a hip replacement in a week, but for humans it might take months or even years. Like most things Moore makes, all indications are that it's almost completely one sided.
Anywho, get a bunch of info on it from Google.
http://news.google.com/nwshp?tab=wn&ncl=1117466940&hl=enTons of articles to read about it.