Panasonic GH2 has a Micro Four Thirds lens mount and currently there are 107 native lenses available for this mount.
Panasonic GH2 doesn't have a sensor based image stabilization system but 31 of these lenses already comes with optical image stabilization.
Since Panasonic GH2 has a Four Thirds sensor, it has a focal length multiplier of 2× so you have to multiply lenses original focal length with this multiplier to find the Full Frame equivalent focal length of the lens when mounted on GH2.
You may also also be interested in these:
Panasonic GH2 Lenses with Image Stabilization
Panasonic GH2 Lenses with Weather Sealings