The last of the TF3 Prequel comic issues come out this week, which seems a little early, with another 6 weeks until the Movie is released. (Probably the TPBs will be released at that time).

Images of covers can be seen here as well.

TRANSFORMERS 3 MOVIE PREQUEL FOUNDATION #4 Of(4) (& it's incentive)
TRANSFORMERS ONGOING #19 (& it's incentive)
TRANSFORMERS MOVIE SLIPCASE COLL VOL 01
TRANSFORMERS MOVIE SLIPCASE COLL VOL 02
TRANSFORMERS RISING STORM TP
The Slipcase Collections are three comics relating to each of the First 2 Movies, in a Slipcase.
TF1 set - Prequel, Movie, Reign of Starscream
TF2 set - Alliance (Prequel), Defiance (Prequel), Movie.