The Linux 2.6.34-rc5 is just a usual late-in-the-cycle release candidate that offers up various bug-fixes from drivers to architecture support to file-systems. There are though some DRM/KMS updates for Intel and ATI hardware with nothing too exciting besides the ATI FireMV 2400 now likely working with the kernel mode-setting code now that it's PCI ID has been added. There's also fixes in XFS, AMD-IOMMU, and many other areas.
The Linux 2.6.34-rc5 kernel release announcement with its short change-log can be read at LKML.org. As always, we continue to benchmark new kernel releases on a daily basis at kernel-tracker.phoromatic.com.