We found this application for what appears to be a 28-550mm 3.5-6.3 full frame zoom.
The other embodiments are for a 15-300 3.5-6.3 for APS-C users.
With tamron coming out with a 18-300 super zoom for APS-C - is Canon looking to update the rather oldish 18-200 EF-S?
As with all patent applications that we show, this is a patent application. This illustrates to us what Canon is looking at in their research labs. It may or may not become a patent, and may or may not even after that be used in a camera system.
Japan Patent Application JP017-134302A
Unfortunately, there's no direct way of linking to the patent application (sad!) however, this is the easiest process to view a japan patent or application.