I remember not that long ago (well at least around 7-8 years ago) where the file systems were still evolving in GNU/Linux, I had a computer that I used to dual boot with RedHat Linux and Windows XP. I remember that those days the "technology" wasn't that impressive with GNU/Linux filesystems (I think it was Ext2 FS), the filesystem had to be manually checked within a certain period.
In comparison with the MS XP superior NTFS which really didn't require much checking (other than a crash, again not always necessary, certainly no "periodic" checks like with Ext2) and way better than the old FAT32/16 and even when you do a manual filesystem check, when comparing with the Ext2/3 checking "time-frame"... NTFS was at least 3 or 4 times faster!.
Also, when entering to a folder where lots of files are stored (say "/bin" where you have 2000 files for instance) then again with NTFS with the same amount of files, still it can load the folder and show you the content with impressively faster times than GNU/Linux, most of the time.
This is not to undermine the hard work of the developers in anyway and I'm really grateful for what they've done for us. For that again, I'm very very grateful. So thank you, so far. Steady wins the race they say :D.
Anyway, apart from that, concerning other improvements, days are passed and now there are a lot of other filesystems for GNU/Linux unlike with MS Windows platform. Not all of them are good nor are recommended for everyone since some FS are designed to be used for Severs, etc not for the desktop users.
The rest assured, the Ext4 filesystem has become the preferred choice among many Linux developers because it's pretty fast, efficient, can handle larger filesystems (up to 1 Exabyte)... journal check summing (which helps to "recover" file systems after a crash, etc) are just a few to name.
But as said before, there always room for improvements. For instance, because of the low power consumption which results in a longer battery life, in mobile/portable devices such as Tablet PCs, etc the standard Hard drive disks are now replaced by the SSD (Solid State Drive). But Ext4 is not optimized for those type of devices.
This is where the never (well it's been there for sometime now) GNU/GPL licensed filesystems like Btrfs comes into the action. Because according to the Ext4's original developer, Theodore To, who has said that ...
"...ext4 is a stop-gap and that Btrfs is the way forward..." Source:- WikipediaBut, Btrfs is still at its beta stage and according to its Wikipage, right now it doesn't even has a fsck (file checking) utility either, which is quite daunting and you should not use it on an unstable computer (where power failure is a typical thing... no UPS... yikes) but the rest assured it does brings new and refurnished features such as ...
|Gaining some speed mate! ;-)...|
*. Efficient at storing small files.
*. Better de-fragmentation.
*. Excellent backup support.
*. Writable/read-only snapshots.
*. Checksum (both data and meta data) - Meaning faster disk check times and less "space" for filesystem corruption, etc.
*. Better incremental backup ability.
*. Faster OS loading times since it efficient.
*. Offline filesystem check and planned Online filesystem check are just a very few to mention.
But as anyone can see, this is not certainly recommended for normal users like you and me to use... but with Fedora/RedHat adaptation (if it happens) and it's not even sure that they'll be able to get it into Fedora 16 but if not with 16 then at least 17 is acceptable :) and if this interest from Fedora about Btrfs might help to speed up the process thus giving the user the ability to "taste" a faster and a more secure filesystem in GNU/Linux in the near future without a doubt!.