As a system administrator one of the biggest pains in my duff is scheduling reboots when kernel patches need to get applied. Enter Ksplice, a way for kernels to get patched without a reboot. Of course, the caveat:
To be fully automatic, Ksplice’s design is limited to patches that do not introduce semantic changes to data structures, but most Linux kernel security patches don’t make these kinds of changes.
This would be perfect for a distribution like Red Hat Enterprise Linux where great pains are taken to not change data structures, in order to preserve the kABI. Maybe the folks at Red Hat will be kind and put this in Enterprise Linux 6… PLEASE?!?