While I have the policy of using ext3 for all new filesystems I create, I still do have dozens of reiserfs filesystems in operation. They're not going away anytime soon. They've been almost trouble free in operation for years, albeit I think that fact can be attributed to the extensive patching SuSE has done to reiserfs in their kernels.
So please don't just assume there are no users of reiserfs left just because its main developer is in prison. I may not like the man personally, never did, but reiserfs is and has been a very good filesystem.