This is the telephoto half of the two kit zooms Panasonic released with the G1 last year.
Its a useful lens in terms of range & in the style of the lumix m4/3 lenses, small & light.
Initial testing suggests its OK in terms of quality, though nothing special.
Its a very useful lens for GH1 video however, with a 35mm eqivalent of 400mm. I don't use long lenses very often, but its nice to have one around when you need it.