It may be a non-issue to the minority of us who can shift decimal points about with ease, but for the majority of humans, currency units need to be scaled to practical values.
You misunderstood, nanoCoins would be integers displayed to the user handled under the hood as 1e-9 BTC.
Transferring 1 BTC to this client would display a balance of 1,000,000,000.
This really shouldn't be worried about
Technically it won't need to be worried about, logistically it will.
You want Amazon to eventually support BTC right? Does their current system support .000001 precision?