For those with keen eyes, the 9th toy in the Studio Series has been suspiciously absent in the last month of reveals... and now we know why - it will be a limited edition exclusive at ToysRUs (which could include us here).
(apparently there was something vague mentioned at New York Toyfair, but I didn't take note of it)

The interesting thing is that this Thundercracker is not a redeco of Studio Series Starscream, or any Starscream toy... it uses the TF5 Voyager Nitro toy with a new head, and is labelled as "Dark of the Moon" (which was when we had a Movie Thundercracker toy released).
The unknown element at this stage though is if this toy was redesigned to have a head that doesn't detach, or, if the head still detaches (like with Nitro).