No, the chinese won't have a field day. Nor will any mug thinking they can whip out a can of spray paint to replicate this for easy cash.
This iPad is £15k because it is a one of a kind iPad (the "Pro" hasn't been released yet), and because it was "designed" by a famous designer. It has nothing to do with intrinsic or tangible value, nor to do with any particular aesthetic of the design. It is everything to do with exclusivity. Exactly the same as when someone pays millions for an old piece of canvas with some paint on it - so that they own it and, most importantly, that nobody else does.
The buyer of this is likely to be someone that makes £15k in less than a day. It will be chump change to them, and a sizeable chunk of wedge to the museum. Fuss over.