Vietnam deposited its instruments of ratification for the 1993 Intercountry Adoption Convention on November 1, 2011.  The Convention will come into force for Vietnam on February 1, 2012.  The announcement from the Hague Conference is here; a notice from the U.S. State Department is available here.  As indicated in this statement, the U.S. position  is that there are important steps to be taken in Vietnam before adoptions to the United States can resume:

The United States recognizes Vietnam’s initiatives leading to this significant development and applauds the Government of Vietnam’s renewed commitment to strengthen its child welfare system and the integrity of its domestic and international adoption process.  We continue to caution adoption service providers and prospective adoptive parents that, to ensure that adoptions from Vietnam can be compliant with the Convention, important steps must still take place before intercountry adoptions between the United States and Vietnam resume.  We further caution adoption service providers against initiating, or claiming to initiate, adoption programs in Vietnam until they receive authorization from the Government of Vietnam.