Yes webp is a google creation. It's basically a single still frame from the vp8 video codec (as used by webm). Being based on modern techniques it gives a better quality for a given size (or smaller size for a given quality) than JPEG and if you have support for webm then implementing webp as well requires very little extra code.
However it has failed to catch on more widely. Afaict chrome is the only major browser that supports it. There is a bug requesting supporting in firefox but it doesn't seem to be going anywhere. IE and safari seem even less likely to adopt it.