It does indeed - but we also see the compromises that were made. It's much thicker than the G12, most of that is the protruding lens. It's not f/2.5, but f/2.8 at the wide end. Where the G12 is f/4.5 at the long end, the G1X is a narrow f/5.8. We'll have to wait and see if other compromises were made in lens design, and how the lens quality holds up to the large sensor.
One more thing occurs to me - I did overemphasize comparisons to EF/-S lenses. Thinking back, the combination of 1/3-stop narrower at the wide end, a very narrow long end make some difference, but importantly, it's a 4:3 sensor, not 3:2, and 4:3 makes more efficient use of the image circle, so all of the lens elements can be smaller than would be inferred from a lens needed for a 3:2 sensor.
Still - the big sensor makes it interesting, and justifies the price tag!