Fast focusing for all - when?
If there are differences in AF speed between the GH1 and new Panny compacts it could be due to the processing speed needed. The processors used in the GH1 may be too expensive or draw too much power to be justified in a compact with a small battery.
There may also be a difference in how fast the sensor can be read out. The GH1 sensor is of a CMOS (NMOS) type and those can read out a part of the sensor (e.g. where the AF point is) whereas a CCD is read out whole. So the GH1 sensor can be read out at 60Hz, but a CCD may perhaps not. It's unclear if Panny's NMOS sensor tech can be scaled down to digicam size and what the cost would be to use it instead of CCD.
And another factor, the small digicam sensor will have worse signal-to-noise ratio which also makes AF harder.
There are also some factors working for the smaller cameras, like more DOF, so less precision needed, and lighter AF groups.
Just my two öre,
Erik from Sweden