As mentioned in the Hasbro MP Soundwave topic (which is now confirmed to be coming out in mid-2013), I asked ToysRUs if any more Masterpiece toys are in their system, hoping it was Sideswipe.... but no, a different Masterpiece toy by Hasbro is coming to ToysRUs at the same time as Soundwave.....
Acid Storm.
A green Starscream redeco, to add to the Masterpiece seeker squadron.
Priced at AU$100, it is $20 more than Thundercracker... so could have a similar price increase in America.
Considering how many Masterpiece toys are coming out of Japan at the moment, I was not expecting Hasbro to release one that Japan hasn't done (yet).
Acid Storm was a classic-verse toy/character that didn't get released in Japan either, so maybe this MP toy is a Hasbro exclusive as well.
(it is worth noting that MP Optimus and Thundercracker are indeed discontinued items in the Australian TRU system - which means stores are not getting any more)