For the first time, THX has shared some of the specifics behind their intense display evaluation program—the battery of tests a manufacture goes through to become THX certified. A fun read if you're a home theater geek: [HDGuru]
THX used to be short for "Thanks", as in "Thanks for making awesome movies with outstanding writing, characters, special effects, and theater standards to match!".
Now it still stands for "Thanks", but more like "Thanks for raping my past by retroactively bastardizing Star Wars and Indiana Jones".
This is just a guess...
(Hearing my nephew say he doesn't like episodes 4-6 because they look old makes me die inside)