The way I figure it, the best thing to do is never try to do anything new. Because if we try new stuff it could fail because it's not as well proven as something that has been being used for years. Like Fat32.
ReiserFS 4 is some realy cool stuff. If it weren't for the wear and tear on the hardware, a perfectly acceptable way to try to save a file from undeleting would be to immediately pull the plug on the computer and hope that you cut power before the file operation finishes.
Imagine a file system that works the way people naturally expect a file system to work.
No journalling. Asyncronous file operations are fast and safe. It's extensable and flexible.
Some weird stuff, though. For example making a file a file AND a directory. Kind or what like Apple's HFS+ does, or some of NTFS's semi-undocumented features]http://patriot.net/~carvdawg/docs/dark_side.html[/L]. (Nice tricks for virus/worm writers though.)
Say you have a file named "helloworld.txt"
you can go:
ls -l helloworld.txt
But you could also go:
ls -l hellowworld.txt/
and see the files inside helloworld.txt that contains metadata, such as ACL's or icons or whatever you want. Much like what is used in OS X. However the way they are doing it would be backward compatable with older apps. You wouldn't have to modify ls to utilize it.
I am thinking that this would be usefull for creating file sharing software to be more compatable with OS X's way of doing metadata, or Windows XP SP2 NTFS's way of storing extra security data in the alternative data streams (that's what is used when download a file and it say's "it's not from a trusted source" type things.). Stuff like file sharing with ReiserFS4 aware SAMBA could benifit from it and be able to more well integrate with other OSes. Or something like that. (all quite a bit above my head).
Although I understand the lack of incentive to add such features to programs, but it could lead to other developements, I suppose.