Despite rumors that R520 may have as many as 32 pixel pipelines, AnandTech maintains that cards will launch with 16 pipes. These R520 cards will carry a Radeon X1800 moniker, and high-end XT and XL variants will be equipped with 512MB of memory. For the mid-range market, cards based on the RV530 will be known as the Radeon X1600 series. Equipped with 12 pixel pipelines, a 128-bit memory bus, and between 128MB and 512MB of memory, these cards are purported to have very low power consumption. Following convention, the low-end RV515 will arrive in the Radon X1300 series. RV515 is a four-pipe design, and as you might expect, HyperMemory variants will be available.
Of course, ATI has yet to confirm any details of its next-gen graphics architecture. Speculation is fun, though, and the AnandTech piece is loaded with plenty of other tasty morsels on pricing, H.264 decode acceleration, and even R580.