2 videos are now up on e-Hobby Shop, showing this special Transformers release in both robot and vehicle mode.
The box art is disclosed as well:
Pre-order has started, and will end on March 31st. It's specified that this is a Japan limited release (国内限定商品), but it shouldn't be a problem for international fans I suppose. Some vendors are able to bring in this limited item to their countries.
Images are from e-Hobby Shop.