Yeah, I will stop visiting the site if the option to use the proper (Classic) interface is removed. I've left other sites over redesigns that weren't as bad as the currently proposed one.
I don't remember the exact date that I signed up for an account here, but I do remember I had been using the site for a bit when registration became available.
I knew this day was coming, and I guess I'm glad that it's taken as long as it has. But it doesn't have to happen; timothy, you can make this stop. I understand your bosses want this to be the new default, but removing the old one *WILL* drive away community. And without community, this site is nothing.