This is a sweet jazzy sound right here!
I just learned this diatonic variation last night!
This is a combination of the 6-5 chromatic walk-down and a 2-5-1. You can see the 6-5 walkdown here:
http://www.learngospelmusic.com/ftopict-15356.html....but instead of walking down from 6-5, you walk down chromatically from 3-2. Here are the chords, I'll post clips later today.
Key C:
E \ A-D-F#
Eb \ Ab-Db-F
D \ G-B-C-E
G \ Gb-B-C-E
C \ E-G-B-D
Try playing with the chords and moving the around diatonically. I've already came up with different variations of this.