16-40 f4 L IS USM

According to a well-known rumors site a stabilized FF ultra-wide might be on the way.

Actually this is exactly what I miss from the Canon system today. On Sony, for example, any ultrawide (or any other lens for that matter) will be stabilized due to the in-body stabilizer. Time for Canon to close the gap. I'd almost blindly preorder this lens, provided there's improved corners too, compared to the 17-40 f4 L USM.