This is a really interesting project between Yamaha and a Japanese design studio called KDDI. I don’t know that we’ll ever see anything like this hit the market as there probably isn’t enough of a market to satisfy. However, who really knows.
The article itself doesn’t tell you too much about the designs, and KDDI’s site is completely in Japanese so it didn’t give me too much to go on.
Even so, what a great idea, a phone with a guitar built into it!