Of course, the big news with this ATI chipset is its built-in DirectX 9-class graphics core. ATI will likely be pushing these chipsets as the perfect basis for a media center PC. Motherboard partners signed up to make boards (or at least listed prominently on the ATI presentation) include Gigabyte, MSI, Shuttle, ECS, FIC, Tul, Jetway, and Sapphire. At least some of those board makers are likely to pair up the Radeon Xpress 200 north bridge with ULi's compatible south bridge, rather than ATI's own first attempt at a south bridge.
Not to be outdone, NVIDIA is making noise about the showing of its own nForce4 SLI chipset for the Pentium 4 at CeBit. That product seems to be everywhere, but it's not officially announced yet. Soon, I expect.