Given that Linux 3.15 is being released this week and Linux 3.16 should be christened around the end of July or early August, it makes sense that Canonical developers are focused on shipping the 3.16 kernel for Ubuntu 14.10. Ubuntu 14.10 has a feature freeze on 21 August, the final kernel freeze on 9 October, and the official release on 23 October.
From today's Ubuntu kernel team meeting, the minutes by Canonical's Joseph Salisbury notes, "We have most recently rebased our Utopic kernel to v3.15-rc8 and uploaded (3.15.0-5.10). We are planning on converging on the v3.16 kernel for Utopic."
There's many features coming to Linux 3.16 as I have been writing about this week with its merge window having opened on Sunday night. There's also a lot of great improvements with the imminent Linux 3.15 as well as Linux 3.14, which will be a nice upgrade for those currently on Linux 3.13 from Ubuntu 14.04 LTS until this October.