Bill Evans was actualy brought back into the band for the recording of Kind of Blue, and really wasn't in the band all that long before that. Miles always dug his playing, and Evans definetly played a part in "inventing" modal jazz, but i guess it didn't work out with him being white and all. Besides they all loved to play over wyntons comping, and it was him who took over for Red Garland in the bop period, so he'd been in the band longer.

http://www.youtube.com/watch?v=qlIU-2N7WY4&feature=related