All the garbage can jokes aside.. I just don't see how something this small can contain the room for dual top tier CPUs, enterprise grade graphic cards and storage while still remaining thermally cool.
Also, some advanced editing suites require specific hardware that require back and or front panel access. Unless theres some kind of breakout box accessory that can be connected to this unit, I don't think this will replace all the functions of the existing Mac Pro.
Go here, scroll down.