Coming up in the Radeon DRM for the Linux 2.6.34 kernel (or releases thereafter) is support for un-mappable VRAM, support for Evergreen GPUs (Radeon HD 5000 "R800" series), use of the Linux power management API for better suspend-and-resume support, better DRM power management, HDMI audio for R700/800 graphics processors, and improved GPU lock-up recording.
Other plans on the code side include better fence for improved lock-up detection, using union to separate ASIC specific data, and better message prints for multi-GPU configurations.
The most common kernel mode-setting problems these days for ATI Radeon customers is coming down to mode detection issues, PLL issues on laptops with Mobility Radeon parts, ACPI/BIOS interaction problems, memory fragmentation, command submission issues, and GPU lock-ups.
Additionally, Jerome is hoping that his R600 Winsys code will be done within the next week or so. After that, Glisse hopes to create a Gallium3D R600 skeleton driver quite soon followed by work on a shader compiler, texture and sampler (will allow Quake 3 to work), various performance optimizations, and then work on the yet-to-be-written R600 Gallium3D driver.