Linux Kernel 3.12 has been released recently and is a stable kernel, meaning it is utterly safe to upgrade to. Kernel 3.12 comes with far more than simple bug fixes. It is pretty much comes with features that will revamp your system performance-wise from the ground up.
The Linux kernel 3.11.6 is out and has brought a few changes and bug fixes along with it. Even if you don’t find any difficulties with your system, you might as well upgrade just to stay current.