I was lucky enough to attend an advance screening of Secretariat tonight. Diane Lane shines in her role as Penny Tweedy, and this movie is just as much her story as it is Big Red's.
Without going into too much detail, the producers definitely took some liberties with historical facts. Riva Ridge is noticeably absent from the film, even though he was a Derby/Belmont winner for those connections the year before. From a pacing and story telling point of view I can understand the decision, although I think including him would have really driven home the point as to how to difficult the Triple Crown is to win, with her having failed the year before.
The one thing that REALLY got to me though is that Sham somehow wins the 1973 Wood Memorial (poor Angle Light!), setting up some extremely painful boxing style press conferences between Team Secretariat and Team Sham prior to the Derby and Belmont. Real over the top stuff here.
I saw this with my girlfriend who doesn't have the racing background most of us here have, so none of the above bothered her, and obviously won't bother the vast majority of people who will see it. Almost everyone inthe theatre loved the movie, and it was definitely an enjoyable two hours. Just realize that dramatic license is part of the process, and even though it will stick out like a sore thumb to us, what we'll end up with is a horse racing movie that all America will enjoy, and engaging and educating new fans is probably more important than appeasing those few of us who can recall the charts of anyone of his starts. It hits every cliche in the book for sports films and horse racing films, but hits them well.
Definite recommendation, despite it's flaws.