Canonical’s Joseph Salisbury has recently announced that Kernel 4.0.5 has been made the default kernel of Ubuntu 15.10 Wily Werewolf, being already used on the daily images.
Next, the developers will implement the Kernel 4.1 (not yet stable) on the master-next branch and most likely, Kernel 4.1 will be used on the final version of Ubuntu Wily.
While the final version of Ubuntu 15.10 will be released on the 22nd of October, the first alpha version will become available starting with the 25th of June, for all the official Ubuntu flavors: Kubuntu, Ubuntu GNOME, Xubuntu, Lubuntu and Ubuntu Kylin. Since Ubuntu (Unity) releases daily builds, an Ubuntu 15.10 Alpha 1 version will not be released.
Also, Canonical has patched some kernel vulnerabilities for all the supported Ubuntu systems and all users are advised to perform a regular system upgrade:
$ sudo apt-get update
$ sudo apt-get dist-upgrade
The same advice applies to the geeks that use Ubuntu derivative systems like Linux Mint, Pinguy OS, Elementary OS, Deepin or others, since they share the default repos of the official Ubuntu systems.