H-Online has a neat preview of Linux 3.9, now in the works.
My favourite item, additional caching ability for Linux:
“Device mapper, which is used by the logical volume manager (LVM) but can also be used independently, now includes a cache target called "dm-cache" (1, 2, 3). This option enables a drive to be set up as a cache for another storage device, for example, an SSD as a cache for a hard drive.”
see Kernel Log: Coming in 3.9 (part 1) â€“ Filesystems and storage
Caching of files in RAM has always been a huge plus for Linux in my terminal servers I installed in schools. RAID 1 was very useful but adding an SSD cache to that would be amazing. Students I used to advise to be careful when clicking should now wear seatbelts and helmets. 😉