Kernel release status
The current 2.6 prepatch is 2.6.11-rc1, announced by Linus on
January 11. This massive patch set includes a new CPU time
abstraction, AMD dual-core support, a memory technology device/JFFS update,
an ALSA update, some CPU scheduler tweaks, a number of latency-reduction
patches, a buddy allocator rework (removal of the bitmap to make life
easier for hotplug memory implementations), the unified spinlock initialization patch, SMP
support for the ARM architecture, debugfs
(which, it seems, is meant to be mounted on /sys/kernel/debug), a
big USB update, an ATA-over-Ethernet driver, mmap() support for
binary sysfs attributes, some power management work, the big kernel semaphore patch, the four-level page table patch, a VIA PadLock
crypto engine driver, a new SKB allocation function, ACPI hotplug support,
the full InfiniBand patch set (covered here last November), a big direct rendering manager
(DRM) rework, a new and simplified file readahead mechanism, a set of
user-mode Linux patches, a big set of input patches, a new set of "sparse"
annotations, an NFS update, an iptables update, support for the Fujitsu
FR-V architecture, in-inode extended attribute support for ext3, some
SELinux scalability improvements, and lots of fixes. See the
long-format changelog for the details.
Note that 2.6.11-rc1 breaks on x86-64 NUMA systems.
Linus's BitKeeper repository contains, as of this writing, a fix for the page fault handler security hole, a fix for the x86-64 NUMA problem, and a few other small patches.
The current prepatch from Andrew Morton is 2.6.10-mm2. Recent changes to -mm include multiple AGP support and a number of fixes.
The current 2.4 prepatch is 2.4.29-rc2, released by Marcelo on January 12. The -rc releases include a number of new security fixes and some driver updates.
For 2.2 users, Marc-Christian Petersen has released 2.2.27-rc1 with the latest security fixes.