http://www.idwpublishing.com/newreleases-upcoming.shtml
# Transformers: Movie Adaptation #2
# The Transformers: Target: 2006 #3
For the 20th...
# Transformers: Movie Prequel #3 (presumably a typo for Adaptation)
For the 27th...
# Transformers Spotlight: Galvatron
# Transformers Magazine #1
This is only confirmed by email, and shipping schedules with Diamond can and do change at short notice, but Megatron: Origin #1 should be June 20th.