I finally got the chance to watch the new John Carter movie today, and I liked it a lot. They did a good job of converting the ERB books into a movie (John Carter covers the first and parts of the second ERB books about Barsoom). The changes made served the story well, IMO. Dejah Thoris was made into a very believable princess for the 21st century. (I figure before long someone will bring out t-shirts with her picture on them and the caption "Yes, as a matter of fact I am a scientist.") Most importantly, the movie caught the breakneck pace of a ERB story but did so while also giving the hero more than one dimension. The movie's John Carter knows that other options exist than being a hero, and he has been deeply scarred by war, but still he can't resist doing the right thing when someone needs help. That makes his heroism all the greater in the battle with the Warhoons. Go see this movie. It's good.
I saw it last night and loved it. Princess of Mars was the first book my father gave me to read when I said I was interested in reading. I was 10 and now 40 years later I see that first book on the screen and was not disappointed. So many people commented that it was a copy of this or that not realizing the story was written in 1912 and the ones they referred to were copies of this work.