I made a patch for kernel 3.4.101 to work on the LS-WXL (Linkstation Duo). It's available for download at http://reauktion.de/buffalo-3.4.101.patch.gz
I took the buffalo kernel sources, created a diff against a vanilla 3.3.4, applied that to 3.4.101 and integrated the .rej where appropriate. Since I'm not a kernel hacker, I might have removed bits, that differed between vanilla 3.3.4 and the version Buffalo used... Also, I did some shortcuts to make sure the files in mach-ferroceon and plat-ferroceon will compile.
Beware: XFS is not working
(not sure if that's because there are changes to the XFS code by Buffalo not distributed or if it is related to the version of gcc used to compile the buffalo kernel vs. the debian gcc-4.7 I use).
I use this kernel to operate my debian wheezy linkstation.