Guys from pcinlife site managed to get their hands on AMD's upcoming entry-level Radeon HD 6570 and Radeon HD 6670 cards that will be based on the 40nm Turks GPU. The Turks and the high-end dual-GPU Antilles are both scheduled to make their appearance sometimes during this quarter.
Both SKUs based on the Turks GPU have 480 Stream processors, 16 ROPs and come with a 128-bit memory interface. The first SKU, or the slower one, will be known as the Radeon HD 6570 card. This one ends up clocked at 650MHz for the GPU and will feature 2GB of GDDR3 memory clocked at 1800MHz. The "faster one", Radeon HD 6670, ends up clocked at 800MHz and features 1GB of GDDR5 memory clocked at 4000MHz.
These two should replace the Radeon HD 5570 and the 5670 cards. Of course, you might want to take these specs with a grain of salt since these cards are still far from an official release.