We argued about it after watching, and the final concensus was: it's a totally metaphorical film. Chirgurh represented death (in a Prince Valiant do) as well as its random unreasonableness, hence his perseverance along with the coin flipping. That's why he simply disappears at the end.
Bell the lawman, is always one step behind evil and death. He always arrives too late. Woody Harrelson represented "life" therefore the white suit, his refusal to carry a gun, and that's why he dies randomly, almost way too early in the flick.
The dreams at the end were Bell's tired musings that he didn't have the energy to chase death and evil anymore, that it's impossible to catch up anyway, so he's accepting defeat... and making a statement about mankind/society. That's what we got from it anyway.