The Obama administration is promising an "audacious" burst of executive policymaking in its final year in office. Republicans are already denouncing such efforts in principle while Democrats, angry at opposition and gridlock in Congress, are welcoming it.
If the President oversteps, such as by closing the detainee operation at Guantanamo, where Congress has enacted tough prohibitions, there could be successful legal challenges. But if his rule-making follows the path laid out by the Administrative Procedures Act, he can probably succeed. The APA, first enacted in 1946 in reaction to FDR's imperial presidency, provides numerous safeguards against unhinged executive power -- standards, timetables, public notice, and so forth.
So relax; wait and see.