lots of interesting things so far.
Everyone knows he wanted Mifune and the movie is like hidden fortress but after he got turned down to make Flash Gordon and wrote the first draft of star wars he went to Toho for the rights to the hidden fortress because they were so similar. he wanted Mifune to come back for his role (now obi-wan) and wanted the movie to have all japanese actors and speak japanese with subtitles even though it was space.

As for Coppola, Lucas said he hated writing and was a horrible writer and wanted someone else to write star wars after he came up with the story but Coppola basically demanded that Lucas write the screenplays for every movie he directs. :'(
Scorsese's interview material is pretty interesting too. Scorsese is the person who introduced Lucas to the girl who Lucas ended up marrying (lucas's wife was an editor for scorsese). And scorsese said Lucas obsessively researched for the movie and said lucas read a bunch of books about the bible in research for star wars.
Everyone buy the book, it is pretty honest and doesn't suck up to George Lucas.