For those visiting the Reiser4 Kernel.org Wiki, it hasn't been touched since last August prior to the kernel.org breach. The latest news on the Reiser4 Wiki is more than one year old. If visiting the patch directory so you can enable Reiser4 support for your kernel, it's 404'ing -- and it's been that way since the kernel.org breach.
There still is some activity these days on the reiserfs-devel mailing list where a patch will appear from time-to-time or a question will be answered by Edward Shishkin, the former Namesys developer who's now basically the only main developer left working on Reiser4. However, nothing radically new has happened in many months.
In fact, the latest patches that have tipped up for Reiser4 are based on the Linux 2.6.38/2.6.39 kernel. The Reiser4 file-system hasn't been officially updated to run with the newer Linux 3.x kernels, but just works with the older 2.6 kernels that are more than one year old.
This week I asked Edward if he plans to even update Reiser4 to support the newer Linux kernel releases. Here's the response from Shishkin:
The most recent patch is reiser4-for-2.6.39. This patch also works for 3.0. Marcin Baczyński also has prepared patch for 3.1, but I didn't check this yet.So the 2.6.39 Reiser4 support can work with the Linux 3.0 kernel, and there is an independent and unconfirmed patch to make it work on Linux 3.1, but nothing newer at this point. Shishkin is just focusing upon stability fixes for the controversial Reiser4 file-system.
Reiser4 will be ported to recent kernels, however I can not specify precisely the kernel version for the port: my time is restricted and now I prefer to concentrate on the stability issues.
In 2010 he originally hoped to mainline the Reiser4 file-system, but that obviously didn't happen. Last October Shishkin mentioned to me that he decided pushing Reiser4 is not a high priority and in January it still lacked mainline ambitions.
One has to wonder whether Reiser4 will ever hit the mainline Linux kernel, even if Edward pushed for it, he would have a tough time getting it approved by Linus and other kernel developers.