The developers have just stated the development of Ubuntu 14.10 (Utopic Unicorn) and they are now looking for the next kernel that will be implemented.
For now, the Linux kernel available is 3.13.x, which is the same from Ubuntu 14.04 LTS. The system is basically identical with the previous one, even if there are some changes that have been implemented already.
“Our Trusty kernel has been pocket copied to seed Utopic. We have opened the ubuntu-utopic kernel tree. The master-next branch is currently tracking the v3.15-rc3 kernel. We likely won't upload a v3.15 based kernel until a few more -rc releases come out,” said Canonical’s Joseph Salisbury in the mailing list.
The new 3.15 kernel wasn't adopted just yet and it will take a while until the Ubuntu developers get the new version implemented, but the groundwork has been prepared.
Ubuntu 14.10 (Utopic Unicorn) already has some daily builds available for download, but they are not for regular users. They are being used to sync with the latest Debian branches and to get a few other packages, but they are not ready for normal use.
The release date for the distribution was also set to October 16, but it hasn't been determined with absolute certitude.