This is the first beta release of the 2.5 series.
Consult the extensive list of changes planned for 2.5. versus 2.4's initial releases.
Our goal is to remove the "beta" designation on Oct 1, at which point the 2.5 family will be the supported release branch for the next year, and 2.4 will be the obsolete branch that will still get critical fixes, but updates will tail off over time.
Please try building and using this beta so that we can confidently make it the release branch by October.