WebP only seems to support 8-bit integer component values, which makes seems pretty backward for a new format.

Higher-bit depths and floating-point components (ala OpenEXR) seem an important feature for any image format that hopes to become a future standard. 8 bits were maybe sufficient in 1990; not so much today. Even microsoft eventually got that clue with JPEG XR...

You only get so many chances to define a new standard, so going with something as lackluster as WebP would seem to be a mistake. JPEG XR, despite its MS origins, seems to be vastly superior. [JPEG XR has licensing issues with the reference implementation (it's from MS after all), but that's not a fatal flaw...]