Read LWN, or check Kernel Newbies, and you'll get a pretty good sense of what's going on. Some of it is some fairly esoteric stuff that's not all that interest

Read LWN, or check Kernel Newbies, and you'll get a pretty good sense of what's going on. Some of it is some fairly esoteric stuff that's not all that interesting unless it happens to be the kind of thing you're interested in. A lot of it is just more hardware support and drivers, which is of course only interesting if you have that particular hardware. But some of it is really great new stuff; cgroups for dividing processes up into groups and being able to control them together, monitoring and limiting resources on a whole group basis. Namespaces (user, PID, network, etc), which together with some userspace tools give you containers for lightweight virtualization (this is what trendy things like Docker use to provide you with instant and easy containers for deploying apps). There are a couple of distributed filesystems (Ceph and Lustre) which have landed in the kernel recently, and there's btrfs which is developing rapidly as Linux's next-gen filesystem, supporting snapshots, checksums, integrated volume management and RAID, and so on. There's reshaping support in the software RAID system, allowing you to change RAID layouts on the fly (going from a 2-disk RAID 1 to a 3 disk RAID-5 to a 6 disk RAID-6, say). There are new SSD caching options, allowing you to use both an SSD and large but slow spinning disk, caching random reads and writes on the SSD, getting the best of both worlds. There are new sandboxing tools that give you the ability to run BPF filters on attempted system calls, giving you fine-grained sandboxing support (used by Chrome to better sandbox the renderer). There's lots going on in the kernel space if you pay attention. You do have to be interested in infrastructure; if you're just interested in applications, you mostly wait until whoever provides your platform (Amazon or Heroku, or Google in the case of Android, or Canonical, or Red Hat) packages these up into a nice, easy to use platform, and you may not ever realize what kernel changes went on underneath to allow these new services. But there sure is a lot going on, and I at least think it's pretty interesting.