It was mentioned in other news postings, but to make sure people are aware of it, both MP Sideswipe & Soundwave will have exclusive extras if you purchase through Amazon Japan (which would only be available to JP postal addresses if buying first-hand).

Sideswipe has a pair of shiny pointy pile-drivers (the toy comes with black blocky ones)
Soundwave has a pair of Energon cubes (the toy MAY come with a single one, making this a set of 3)


(personally though, the Cubes are way too big, despite being to scale to Soundwave's chest... and don't look very interesting if empty instead of energon-filled)