@Lucien: I think it helped that I didn't see Ray. That never entered my head.
I can totally see the similarities but did the makers of Walk the Line have 'Oscar potential' in their heads and purposely want to make a movie to mimic Ray? One of the producers of Walk the Line was John Carter Cash (the only child Johnny and June Carter had together). Speculating - maybe he saw the success of Ray and thought hmmmm. I don't know specific production dates to test that theory.
I'm just being a devil's advocate
Also - Just tell that nagging voice to kiss your a** (problem solved).