Just like the surprise find of a wave 2 small Authentics toy (Grimlock in Australia first), a wave 2 of the large size has been found in Asia and America in the last two weeks, which has Megatron... which looks to be like the others, in that it is an enlarged small-size Authentics toy, with more joints and sculpting.
That just leaves Starscream left to be released in both size scales.