I agree hyperinflation is highly unlikely in our current weak economy. As to who would be helped or hurt, those with a highly leveraged balance sheet–whether personal, business, or government would be beneficiaries, as the value of the future payments decreases. Those hurt would be anyone owed that money, such as holders of long-term bonds, mortgage lenders, etc.
Yes, our situation increasingly resembles that of Japan, which has had two decades of near zero growth after their credit-driven real estate mania climaxing in about 1990. By the late 1980s it looked like Japan would take over the world. Now their stagnant economy, along with a demographic trend of low birth rates and actually declining population gives them a grim future. Their policy response to the stagnation also resembles ours–easy monetary policy with near zero interest rates combined with the fiscal stimulus of massive and arguably unneeded infrastructure is a little like ours. Their reputation for quality products and a hard-working population seems to be carrying them for now.