VR Zone spotted some info about upcoming DirectX 10 mobile GPUs from ATI on Beyond3D's forums:
According to him, M76XT is high-end 65nm CrossFire capable DX10 chip with UVD will be replaced by M88 in the first half of 2008.
M88 is made on the 55nm process, supports DX10.1 and PCIe v2. In the midrange the M76, 65nm CF capable DX10 chip with UVD will be replaced by M86, which is also made on 55nm and supports DX10.1 and PCIe v2.
For the low-end part, we will see M72/M74 chip being replaced by M82 which is also made on 55nm and has Display Port support, DX10.1 support and PCIe v2.