They are small, low power, and silent. Hopefully cheap too. There has been a gap for stuff for applications like building your own tablet, netbook, robot, media centre, home automation, helicopter, 3d printer etc that people are looking to these to fill, especially now that the graphics are good enough to do video which previously ARM SoCs couldnt. You can have something under 5W a few inches square with integrated interfaces for not much money soon.