The film is still set to be released on the 65th anniversary of the musician's birth -- February 6, 2010, so this change shouldn't disrupt anything. As for Demme's involvement, it shouldn't change things much. He's made docs on both the Talking Heads (Stop Making Sense in 1984) and Neil Young with Heart of Gold in 2006. And Ziggy seems cool with the whole change: "His empathy with my father's body of work and his unique understanding of the musical documentary form makes me confident that this film will be the ultimate celebration of my father's life."
Scorsese, meanwhile, still has other famous folks to keep busy with -- George Harrison, Theodore Roosevelt, and Frank Sinatra. Which one should go first?