The GH3 is getting bigger that it's older brother the GH2.
GH3 Size vs GH2
The GH3 is about the same size of the Canon Rebel T4i
GH3 Size vs Rebel
Here is the Front of the camera
GH3 Front
GH3 Back
GH3 Back
The top is where it gets interesting. They have relocated the stereo mic's to the top back of the HotShoe. There is a WiFi icon. I am so glad they relocated the White Balance, ISO and Exposure Compensation buttons to just behind the Front Control Wheel.
GH3 Top