in a moment of boredom, I was scanning through the 43rumors site, and the 12-45 announcement indicated $680 USD as the opening price. I wonder if that will go down, or if it will be bundled with one of their newer cameras? In the comments, someone suggested it will eventually end up on auction as an open box item. I know that's just guessing, but it could make it an interesting alternative to the 12-40 Pro. I rented that lens when I still had an mu4/3 camera, and the IQ didn't make up for the impression that it made my camera highly imbalanced, for me, at least.
EDIT: just saw it's $650 on Amazon US. Time will tell. It's reasonably small for what it does:
Amazon pic