According to the press release, "The new PS3 with 12GB flash memory offers opportunities to experience the world of PlayStation at an affordable price point. Users can also expand the storage capacity of the new PS3 with 12GB flash memory by connecting a dedicated HDD (250GB) to be released concurrently with the new PS3 . In addition, a variety of accessories will be introduced by SCE to meet various kinds of needs from users including a vertical stand that offers more flexibility in how the new PS3 can be displayed."
The 500GB and 250GB models replace the 320 GB and 160GB models respectively at the same price - $299.99 USD for the former, $269 for the latter.
The Super Slim is half the size of the original launch PlayStation 3, while only 1/4 lighter than the current Slim.
The Super Slim 500GB model will launch in the UK on 28th September, while the more wallet friendly 12GB flash memory version launches on 12th October.