I switched from QWERTY to Dvorak over ten years ago, and I am crippled going back to QWERTY. I apologise routinely to students and colleagues whilst using their keyboards, explaining that I'm no longer used to the QWERTY layout.
Hey, I didn't say you should stop typing in QWERTY! Wink. My point is that people who want to learn it won't replace their QWERTY skills -- They'll just learn another one. A brand new superpower.
It helps me to have a sensory key over which set of habits to use. I usually use Dvorak, and don't look at the keyboard. If I look at the keyboard, I get QWERTY.