Jason Kottke has a nice overview of the disruptive potential of smartphones, using the iPhone as an example. He compares the current state of smartphone development to the early stages of the Internet. If correct, that comparison would leave a lot of headroom for smartphone disruption. Even if you believe that smartphones occupy a totally different market space, you may still be in the crosshairs.
Somewhere, a few coders may be planning to replace your brand with an app.