The official Transformers Facebook page has recently updated with the first promo video for the upcoming Transformers: Combiner Wars cartoon series. Keep in mind the final product will not be a stop motion production like what can be seen in the trailer. The promo features Optimus as he is traveling on a battle destroyed Cybertron. Here Prime witnesses the destruction that the “Combiner Wars” has caused, before he confronts Megatron. This confrontation proceeds to be the final onslaught between the two warriors. Transformers: Combiner Wars is set to premiere exclusively on the GO90 network on August 2.
EDIT: The trailer has also been posted to the official Machinima Youtube channel.
Source: Transformers Facebook