Russia and the United States signed an agreement on nuclear cooperation, usually referred to as a 123 agreement. The document was signed by the head of Rosatom Sergei Kiriyenko and U.S. ambassador to Moscow William Burns.
The agreement has a long history - it was reported to be "almost ready" more than a year ago. The delay was apparently caused by doubts about Russia's policy that existed in the U.S. administration. Although the administration agreed to proceed with the agreement, it would have to be submitted for approval to the U.S. congress, where it would have to overcome substantial opposition of many lawmakers.
Over all, signing of the agreement is a very positive development in the U.S.-Russian relations, since it would create numerous opportunities for cooperation and partnership.