Hi dig,
no. it's not conceivable.
a lot of the fed's balance sheet is obligations to the treasury.
reversal is just a signature away. easing becomes tightening.
right now, the aim is to convince the markets that inflation is possible. if they can get some inflation and not let it get out of control, this can create real benefits to important parts of the economy: the value of old debts will diminish against the value of current economic performance and long term assets.
in the meanwhile, reduced mortgage obligations implies raised house prices, increased private equity and more consumption. dollar should also decline in value making exports more competitive.
qe is basically the flip side of tightening in an inflationary environment. qe loosens up money in a deflationary environment. this is what you want, so long as you control your own currency.
what's missing from this scenario is actual government spending on infrastructure. what the fed is doing can only do so much.