Wind power has been subsidized by the federal government for 20 years, with several expirations and renewals occurring along the way. The most recent expiration was scheduled to occur December 2012 along with many other federal programs bundled into the fiscal cliff. Many expected the wind subsidy to be renewed (and it was on January 2, 2013 when President Obama signed the American Taxpayer Relief Act of 2012).
But the chance that it might expire encouraged wind power producers to launch new facilities before the sun set on 2012 Q4. The end result: high pressure and lots of nail biting for those in the wind industry, but more renewable power for the United States.
For more info, see:
Wind energy tax credit set to expire at the end of 2012
Planned wind turbine additions rise in advance of scheduled expiration of wind tax credit
Updated info here: Wind industry installs almost 5,300 MW of capacity in December