According to AJIL's notice:
'Nominations are based primarily on scholarship and creativity, as demonstrated in books, articles, and other written work appearing over a period of years, including, but not limited to, publications in the Journal. Other factors taken into account include areas of expertise or professional perspective or discipline.'Nominations, including "supporting statements and information, such as a curriculum vitae, a list of publications, and, if possible, copies of significant publications," should be sent to the AJIL Nominating Committee Chair, in care of either one of the Co-Editors-in-Chief, Columbia Law Professor Lori Damrosch or Miami Law Professor Bernard Oxman, via the contact details here.
Deadline for nominations is September 15, 2012.