He has also confirmed that the device will have a Real-Time Clock (handy for games like Pokemon on the Game Boy), pogo pins on the bottom for IO expansion/accessories, Hall Effect analogue sticks and a D-pad which is placed above the left-hand analogue stick.
He has also stated that while the default button layout will be the traditional four-button diamond, users will be able to "swap out the front shell and change a daughter board to get six buttons."
Taki Udon has also revealed the internal codename for this product, Super R2, along with an image of the Plan A version – which appears to have handles.