Very simple use case: connect keyboard and mouse and you'll get portable linux workstation. It's a pity that there is no hdmi out but you shouldn't expect a lot from $200 tablet. As a bonus you'll have lots of open source packages (including various development tools) that will run just fine on this relatively powerful hardware. Most of the user-friendly ubuntu apps won't be usable without a mouse. There are also lots of keyboard-oriented applications that might be fine with just a keyboard.