Russian President Vladimir Putin signed the document to pardon imprisoned oligarch Mikhail Khodorkovsky today, December 20, 2013. The document comes in effect immediately after it has been signed. Khodorkovsky may thus be released from prison on December 20 as well.
Putin made the surprising announcement about his intention to sign Khodorkovsky's clemency petition on December 19th, after his large press conference at the Moscow International Trade Center.
Mikhail Khodorkovsky was supposed to be released from prison in August 2014.