The web is also full of doubters, nay-sayers, forum flamers and rumor starters, too. Just saying.
What kind of proof do you need? Corning doesn't etch their logo or apply stickers to their products. There's no special code or laser engraved insignia.
Corning Gorilla glass is used on a large number of capacitive touch screen devices including HTC devices, Samsung Galaxy S devices, Apple iOS 4 devices, Moto touch screens and more.
Given that Corning partnered with Samsung to build a Gorilla glass factory on Samsung property exclusively for use on Galaxy S devices (do your own research, Google is your friend) that's about as proof as it gets.