It would seem that Hasbro has been keeping a very tight lip about any info regarding the upcoming Transformers: Prime cartoon. However, Amazon.com has a listing for a graphic novel based on the upcoming series that may shed some light on things. The listing for this book gives a description of it that could very well reveal the plot to the upcoming Prime cartoon. The product description reads:

"This all-new graphic novel adventure leads directly into the all new Transformers: Prime animated series! In this epic first adventure, battles across Cybertron have left Bumblebee and his fellow Autobots in need of a new leader. But is there anyone who can step forward against the threat of Megatron and the evil Decepticons?"

This seems to indicate that the book is about the early days of Optimus Prime being the leader of the Autobots. Could this be reflected in the cartoon? Only time will tell.