Sabayon 13.04 is the project's first release where systemd is optionally available to its users while the feature is still considered a bit experimental and they are not yet prepared to abandon OpenRC. The project says that using Systemd yields a 4x boot speed boost compared to OpenRC, among other benefits.
Also new to Sabayon 13.04 is what the project deems "production ready" UEFI support along with handling Secure Boot just fine. The updated Gentoo-based distribution is also using TMPFS by default for mounting /tmp, as has been the theme set by other Linux distributions as of late. The project is also moving over to GitHub for its development repositories.
More details can be found in the Sabayon Linux 13.04 press release at Sabayon.org.