Actually YOU are incorrect. Its the iPhone 5 with a larger battery and a colored polycarb rear shell.
Beg to differ. There are multiple components that are different, as seen in the leaks and demonstrated in the keynote. It has more LTE bands. Have to wait for the teardown to know for sure, but the screen seems to have slightly different tech specs. The logic board (according to leaks) is different. The same CPU and screen size do not make it the same phone.
And to the other dissenter - did the iPhone 5 have STEEL in the frame? This is probably a large part of why the 5c is heavier than the 5.
It's amazing that people will imply that the 5c is the innards of a 5 put in a new case, when it's so easy to visually see that's not the case.