The hawk-eyes of the internet spotted this interesting lens patent submitted by Canon. It's for a lens that can be reversed and used as a macro lens. While this can currently be done you need an adapter. Plus you lose any communication with your camera. You have to do all focusing manually and most modern lenses aren't even capable of it. But if this patent leads to an actual product, you'd essentially be getting two lenses in one.
This is a pretty cool prospect and we'll see if it leads to anything in the future. You can read more about it HERE