The idea sounds fantastic, but what will give the "e-dollar" any intrinsic value? 1 US dollar is basically paper with ink on it. If it's not worth anything, there's no point.
I'm thinking that the e-dollar will have the same value as $1, guaranteed by the Fed. As if BitCoin had a constant exchange rate pegged at 1.00 against the US dollar. BitCoin can never achieve this, the the e-dollar can.