The USPTO has published its final rule regarding changes to implement micro entity fees. The rule includes qualifications to receive the seventy-five percent fee reduction for those who qualify. More information is available from the Dec. 19, 2012 Federal Register at
http://www.gpo.gov/fdsys/pkg/FR-2012-12-19/html/2012-30674.htm or
77 Fed. Reg. 75019 [PDF]