Re: What are you excited about?
I've been digging into Arduino lately. You might be interested to learn of this component.
(There's also this.)
Love Adafruit! I strongly considered Arduino too. The main reason I went with the Pi was because I can use gphoto to control the camera's shutter, ISO, and aperture. You can typically get shutter control out of an Arduino, though.
As for motors, I'm using steppers rather than servos, because of the specific functionality I'm going for. I'm looking for exact precision in the start and stop points. I've got a cool idea for the control UI, and I'll post about it at some point. Just focusing on getting the machine to work first!