As a reminder, Ubuntu 15.10 Wily Werewolf is scheduled for release on the 22nd of October 2015, for now being in its early development stages, only daily builds being available.
While there isn’t much information about Canonical’s upcoming system, the Ubuntu developers have announced that Ubuntu 15.04 will be using either Kernel 4.0 or Kernel 4.1, if it gets released in time. For now, Kernel 4.1 is only available as RC release.
Canonical has recently implemented Kernel 4.0.4 on Ubuntu Wily and announced that they are tracking the kernel 4.0.x release in the wily master-next (stable) branch and the kernel 4.1 series on the unstable branch.
Because the Ubuntu and the kernel releases are not synced with one another, everything depends on what is the newest stable kernel available until the Ubuntu system gets into the Kernel Freeze state.
The good news is that either Kernel 4.0.x or Kernel 4.1 include the long awaited Live Patch Feature that permits users to install new kernels without having to restart the system.