Why is every tablet assumed to be inspired by the iPad? All sorts of companies have been creating tablets for a long time.
Sure Apple apparently made a nice one. But it is not only Apple's genius, it is also the the progress of technology that made it possible (faster, more power efficient CPUs, better batteries, better displays...).
One big thing hindering other companies' tablets was probably Windows, which presumably just sucked too much. There were attempts with Linux tablets, but again, the sleekness wasn't there yet (in the meantime, as with the hardware, things have improved).
So now Google has their own OS, so they can make a new attempt at creating a nice tablet without Windows suckage. They are not just copying Apple.