The discussion being had isn't about Reiser4, the experimental file-system that's not mainline in the kernel and was developed by Hans Reiser prior to being convicted of murder. The discussion is about what to do with ReiserFS given that the file-system is losing popularity and even upstream Debian developers have been abandoning the journaled file-system that was introduced in 2001.
Debian Linux has already removed ReiserFS support from the Debian Installer. Ubuntu and Canonical developers really aren't interested in maintaining ReiserFS support themselves without Debian. A discussion was started today on the ubuntu-devel mailing list about what to do with ReiserFS support, up to and including disabling the module from the Linux kernel.
So far in the discussion it appears the developers want to keep the ReiserFS file-system module around, but that they'd be okay with having the ReiserFS capability removed from the Ubuntu installer.
Are you still using ReiserFS on any production systems or have you moved on to EXT4, XFS, or even Btrfs? Let us know in the forums.