The Jetpower Optimus Prime toy is priced at 7140 yen (with tax included), which is the price of a Leader class toy. On the other hand the new Megatron is priced at 4410 yen, the price of Voyager class.

kurdt and I suspect that Jetpower Optimus is either the old Voyager mould but with new Jetfire parts to make up the Leader class price point, or a complete new Voyager size mould of Optimus altogether.

From the description of the Megatron toy in Japanese text, it seems to be a simple metallic repaint of the ROTF Voyager Megatron mould.