"We had some time to tinker with this latest and greatest Linux, and it's my kind of Christmas present: solid improvements to my favorite operating system. Here are the five features that I think most of us will appreciate the most as we move into the New Year.

"1) Ext4
The next step up in Linux file systems, has finally arrived. Ext4 improves, well, everything about hard drive storage. It gives you larger file-system and file sizes, faster I/O, better journaling, and it can defragment your drive on the fly."

http://blogs.computerworld.com/linux_2_6_28s_five_best_features