Canonical's taken the next step in pushing Raring Ringtail out of its nest by releasing the very first beta version, but only for Edubuntu, Kubuntu, Lubuntu, UbuntuKylin, Ubuntu Cloud, Ubuntu Studio and Xubuntu. Plain ol' Ubuntu for desktops and servers will arrive with the final 13.04 beta release on March 28th, so that devs will be able to focus on the software and keep things under wraps for a little longer. These early versions aren't for the faint of heart, but adventurous folks can download them at the source if they don't mind some kinks. However, those who aren't interested in tempting fate can wait for the polished release in April.
Canonical Ubuntu 14.04