Over time, I can see this being a standard feature on guitars. Like it or not, this is the future, once it gets into the realm of 'everyman' affordability. (ie, Korea or China can mass-produce it) Why? Because it will sell itself to the legions of n00bs picking up the guitar for the first time. And that is what all those music super stores focus on. (The last time I went into a Guitar Center and actually looked for a guitar that was aimed at the professional working guitarist, I found ONE, but it was the awful Floyd Rose guitar)
Being able to hear A440, tune, and intonate your instrument should be required for all guitarists.