Wow, I can't believe this debate lives on. I thought it was rather common knowledge that Dimebag used the real thing from Bill and Becky.

Reading through it does make a few things jump out at me:
1) For all we know, the guy himself may have been confused on what Stew-Mac sold. He probably knew he had the real deal in his guitar, but who's to say just how up he was on Stew-Mac inventory and the Bill vs. EZ issue?
2) Even if he was as big of a gearhead as people posting on the internet, that still doesn't mean anything. Famous guitar players are notorious for not giving away tips and secrets. Jimmy Page made a point out of no longer giving away too many studio gear secrets because too many people copied his earlier comments and made some gear (e.g. little old Supro amps) hard to find.
3) The Seymour Duncan deal could mean nothing one way or another. Maybe it was because Washburn couldn't get the good pickups anymore. That adds support to the Bill/Becky position. Then again, maybe we read to much into it. Maybe Dimebag wanted to make a few bucks through an endorsement deal with Duncan. Lots of guys do it. Who knows?
"To crush your enemies, to see them driven before you, and hear the lamentation of their women." - The Governator