This list has been assembled based on the various rumors, confirmed images and in consultation with some of the most reputable rumormongers out there.
June 6: Space Marine Devastators + Codex (CONFIRMED via images)
June 13: Space Marine Terminator Librarian + X (Command Tanks?) (Librarian practically CONFIRMED)
June 20: Dark Angels Interrogator Chaplain + Codex (Chaplain seen)
June 27: X (Citadel Colour sets? Many of the older ones are currently out of stock)
July 4: Age Of Sigmar (CONFIRMED via images)
~More as we get it.