They're literally just licensed X-Keys with some fancy backgrounds printed for them. There's nothing stopping anybody from building this setup at this very moment, cheaper than CH is going to offer it. All it takes is the X-Keys, and a color printer.
Hell for not much more, you could use Phidgetts USB gear (from
http://www.trossenrobotics.com) and built yourself.. well, anything you can think of. Not just limited to glorified keys, but potentiometers, sliders, touch pads. Wrap it around an LCD display made for car headrests, plug that into your extra monitor output, and (a simple example), and you've got a pretty sweet garmin gps stack for the MS Flight Sim series.
Then we can all quietly hope that HT will one day allow us extra monitors (and hopefully a data out file) and then really build some setups with great immersion.