Does anyone know if Ikaros and Tomoki end up together in the end? And when is the third season coming out?

As much as I would like to say they do, its not known. Sora no Otoshimono, is, as you know, a harem. Most harems don't have the main character end up with just one girl, because they wouldn't want to take a chance and ruin it for someone. The third season was supposed to come out last Christmas, so hopefully it will be this years natal gift instead.