In February 2007 The American Bar Association approved a Code Governing Assisted Reproduction. The proposed Model Code Governing Assisted Reproduction was drafted by the American Bar Association Family Law Section Committee on Assisted Reproductive Technology and Genetics, under the Charimanship of Charles P. Kindregan, Jr. Distinguished Professor of Law at Suffolk University. The draft of the Code was initially approved by the Council in May 2006. You may read the revised draft approved by the Section Council in February 2007 here.
An interesting discussion on embryo adoption can be read at the blog of Maurice Bernstein, MD here. You will find the comments worth reading also.