I stopped at a camera shop in NYC today and they had the X20 in stock.
I've always liked the X10 but the improvements to the X20 seem to really make this a pretty nice upgrade. The new viewfinder with shooting info and focus boxes/confirm is fantastic! As you can tell I did buy one.
The changes to Auto ISO are also quite awesome. You now have the ability to both set a min shutter speed and in combination with OIS you can also have the shutter speed further increased if the camera detects movement in the scene.
Changes to the AF box selection is also much faster...I know the X100S also implemented this change.
With just a few shots taken colors seem very natural and similar to my X-Pro1.
Not a camera that I'm likely to manual focus all that much but focus peeking is a nice addition.