Thank you, that's a very helpful tutorial, but I DO see some room for improvements.
For instance, you show 'processing 2' pics, but I didn't see where you linked or mention to get Processing V2 libs for firmata as they are not included in the Processing V2 distro.
Also, I think adding comments indicating the codes purpose is important to keep arduino v processing code separated in my brain.
Other than that pedantic rant... great job.
I bet you forgot that was an additional step to install the firmata lib in processing... for that matter, that's where some Q's still are in my head. But many others were answered, and I bet I would stumble upon answers to my remaining Q's if I played with it a little.