DSLR magazine published an interview with executives from Panasonic and they confirmed that the replacement of the Panasonic GF1 will not have the new 16.05MP sensor from the latest Panasonic GH2 camera.
About the GH2 16.05MP sensor (from Panasonic's website):
"The newly developed 16.05-megapixel multi-aspect Live MOS sensor adopts the high speed digital νMaicovicon. In addition to the high speed, which is an advantage of the CMOS sensor, Panasonic adds its original pixel mix technology. A dedicated process exclusively for νMaicovicon of the DMC-GH2 is newly developed by applying the top-class high performance transistor and its interconnection process needed for the high speed operation of digital circuit to make low-noise photodiode and transistor with reduced wiring to achieve both high resolution and high aperture-ratio as the DMC-GH1. The result is both high resolution and excellent S/N are realized with more than 3dB improvement of noise and 200% high sensitivity in the DMC-GH2."