According to the Washington Post, 

Attorney General Eric H. Holder Jr. is set to announce [today] that low-level, nonviolent drug offenders with no ties to gangs or large-scale drug organizations will no longer be charged with offenses that impose severe mandatory sentences.

Holder plans to give this speech in San Francisco at the American Bar Association.  The speech is also expected to outline changes in policy towards incarceration of the elderly and non-violent criminals.

Hat tip to David Downs.