Last week the Ubuntu kernel team opened up their first kernel v3.14 re-base that was pushed to the ubuntu-trusty unstable branch. Today was another kernel team meeting and the kernel status update from the meeting minutes reads "We have packaged our 3.13.0-9.29 Trusty kernel and uploaded to our canonical-kernel-team ppa. This primarily pulls in the latest v3.13.3 upstream stable updates. We have also started tracking the v3.14 kernel and have recently rebased our unstable branch to v3.14-rc3."
Many users have been hoping for a Linux 3.14 kernel by default in Ubuntu 14.04 LTS but that remains to be seen. The feature freeze is this week for Ubuntu 14.04 and this morning we found out Mesa 10.1 should go in at the last minute while the 3.13 kernel is still what's in Trusty Tahr stable. The final kernel freeze isn't until the start of April but it will be interesting to see if an exception is made for pushing Linux 3.14 into Ubuntu 14.04 (if at all) during the feature freeze period, especially given this is a Long-Term Support release.
Linux 3.14 is sought after for improved hardware support (particularly with the upcoming Intel Broadwell processors and new HD Graphics but also for better GPU hardware support in other drivers) and other new Linux 3.14 kernel features.
If Linux 3.14 doesn't make it in cleanly, Ubuntu will end up with another "franken" kernel where lots of kernel patches are back-ported onto their 3.13 code-base. At least though with Ubuntu 14.04.1 and future Trusty Tahr point releases they will continue in shipping new kernels and other Mesa/X.Org packages, etc. Ubuntu users can also opt right now to use the Ubuntu mainline kernel PPA, which is a convenient source for Debian packages of "vanilla" kernel releases along with daily kernel snapshots -- making for convenient testing of new kernels.