Though a few of the buttons and controls are different and it has a fixed, traditional LCD instead of an articulated touch screen, the G10 uses basically the same body as the G2. I generally like the overall design and it's comfortable to grip and shoot--even one-handed with a heavyish lens.
I really miss the dedicated movie-record button that's on the G2, but otherwise the mode dial and drive mode options, as well as the dedicated Intelligent Auto button, are identical to the G2. The Cust slot holds three custom settings.
One of the differences between the G10 and G2 are the video capabilities: in addition to its 720p Motion JPEG QuickTime compared to the G2's 720p AVCHD Lite, the G10 lacks the G2's admittedly limited aperture (Peripheral Defocus) control.
In what I presume was a cost-cutting measure to hit the G10's cheaper price point, Panasonic left the focus mode control on a dial but put the focus area selections--single area, continuous, face and tracking--into a menu brought up by one of the nagivation buttons. I think I prefer it there, anyway.
One of my least favorite changes between the G1 and G10 (and G2) is the relocation of the SD slot from the grip to the battery compartment. Yes, it's a very common location in point-and-shoots (and the Olympus models), but it's annoying if you use a tripod and awkward if you take the card out frequently.
Overall, the G10 has intelligently laid-out and easy-to-understand controls that will likely be understood by anyone who's used a relatively sophisticated compact camera (off Auto, of course). The Fn button can be programmed to pull up settings for film mode, aspect ratio, quality, metering, Intelligent Resolution, Intelligent Exposure, extended zoom (a form of digital zoom) and guide lines.
The jog dial, which could really use a label for better discoverability, controls exposure compensation, aperture and shutter speed.
Though there's a lot of things to like about the G10, the EVF isn't one of them; it's one of the smallest, lowest-resolution and uncomfortable models I've used in a while. Though I eventually became accustomed to it, it remained disappointing.