In my opinion (cf. http://desgeeksetdeslettres.com/blog/jeux-medias/studio-independant-concurrencer-diablo-3-avec-un-jeu-telechargeable), Grim Dawn Diablo 3 out before because the Crate Studio E. is independent and not take the risk of encountering Diablo 3. If D3 comes out in December 2012 as expected given the delay what will have been irreparably Blizzard, it leaves time to Grim Dawn released in the fall of 2011 or the limit in June 2012.