The Society for Research in Child Development (SRCD) has established a new journal this year, called Child Development Perspectives. The December issue includes a special series of articles (11 in all), under the rubric "Emerging Adulthood Around the World" (Table of Contents).
Consistent with the theme, several articles report on EA in different regions and countries of the world. There's also a debate between Jeffrey Arnett, who first proposed the specific stage of EA in 2000, and EA critics Leo B. Hendry and Marion Kloep.
From my initial skimming of several of the articles, they appear to provide a lot of interesting material on EA, and where it should go from here.