Loved the guy. I used to mimic his style on "Here comes the Sun" and "Handsome Johnny." It's been awhile but IIRC on the latter the strings made an open D chord when you pressed the 6th, 5th, 4th, and 3rd strings with your thumb on the second fret. No wait, it was the open D form on the 4 lower strings but an open E when you pressed on the second. It's cool cause you don't have to tune the first two strings down. That's how he got that wild sound with just his thumb coming over the top. Take it off and there was some brief dissonance, or something.
There will be no replacement, broke the mold, etc.
Audio only but it's him:
http://www.youtube.com/watch?v=viqe5AE4ONc