It may be bullish for the market for the time being but I wouldn't call it a positive thing overall and I'm afraid we will have to face it in the future when the US government starts manipulating the market in order to earn profit to cover their gaping budget deficit...
Short term benefit and Long term as the opportunity cost.
People are used to been more interested in the Now than later.
Such market manipulation may not be beneficial for the majority of them though considering that in the scenario when the US government is carrying out market manipulation they'd want to make profit which means they have to pump and then dump on people to make money. Those people getting dumped on have to be the majority of traders and they have to lose money for the US government to make a profit...