Interesting idea.
I have had a quick look at your Getting Started and at your Blink example.
What I don't understand is whether the user needs to write an Arduino program as well as CSS code in Chrome. Or does all the code go into Chrome and the Arduino part gets uploaded in the background without the user being aware of that.
It may make things clearer if your example included one (or two) complete files for download.
And how is Chrome communicating with the Arduino?
...R