Unless you manually upgrade your kernel and other system packages from your Ubuntu 14.10 installation, Ubuntu 15.04 Vivid Vervet is an important release for users of new Intel Broadwell systems for ensuring your hardware reaches its maximum performance potential.
While Ubuntu 15.04 is still three months out from being released, it already contains a newer version of the Linux kernel and other packages than what ships out-of-the-box on Ubuntu 14.10.