Moderating output will cause a surge in prices, right now expected to exceed $60 per barrel in the first few weeks. This is immediately going to affect big oil consumers, especially airlines. Hopefully American producers will be able to get themselves out of their current slump and ramp up production as well with the higher market prices reviving their profit margins. Higher oil prices could also serve as a "bridge" into economies becoming less oil dependent.
Ultimately, there seems to be more positive than negative effects on the US economy because of this deal, but only time will tell.
http://www.economist.com/news/finance-and-economics/21711088-oil-prices-surge-saudi-arabia-and-iran-sign-deal-opecs-meeting