Was this a product that has yet to see release? Or an unannounced edition that has since been canceled after some were already produced?
Well it turns out it is indeed an upcoming product that was not released at the time. As fellow Seibertronians Emerge and Sabrblade informed us, this is actually part of a Platinum set featuring redecos of both Classics Optimus Prime and Megatron.
We know this now because Allspark member lastmaximal found the actual set at a specialty store in the Philippines. It seems that the copies found on e-bay are the finished product since the deco is unaltered between what we have seen and what is shown on the box with Optimus having unpainted translucent blue parts in the front of his vehicle mode.
Megatron himself has the translucent plastic theme going on as well with the gun shell being a translucent red. Also, the rerelease of the Classics Megatron gun toy means that unlike what was stated on TF Wiki, Hasbro's policies for these types of transforming toys (toy guns of any kind) are more lax then previously believed.
So, is anybody interested in picking this set up? let us know on the boards!

Update: here are some extra images of the Optimus Prime, found on weibo