If you believe the rumor mill, it loks like Apple just may be releasing a successor to the iPhone 5C (which they cancelled). According to sources, a new "6C" could be coming and arrive in the 4-inch form factor. As much as this could make sense, I don't see Apple doing as they scrapped the 5C due to low sales volumes. Then again, if you bundle one of these with an Apple Watch Sport, it may just make a few extra sales.
According to Future Supplier, the obtained casing looks very similar to what is currently available on the iPhone 5C. The only notable differences that can be seen that suggests this could be the rear housing of a refresh model is the additional speaker perforations on the bottom and an update to the camera flash cutout.