The first release candidate of what will become SilverStripe 2.4 is now available for testing. For a full breakdown of the new features, you can read the following blog post regarding beta 1 which highlights the new options built into 2.4: http://silverstripe.org/silverstripe-2-4-beta-release-brings-hierarchical-urls-sql-server-support-and-much-more/.
From the blog post:
Today we've moved significantly closer to a final and stable version of SilverStripe v2.4. You can now download SilverStripe v2.4 Release Candidate 1, which fixes bugs and incorporates feedback from the community since our Beta releases.
We'd appreciate you testing this release, and seeing whether your existing sites upgrade smoothly to this version. Version 2.4 does represent a major version update, providing a number of new features needed to run larger and more complex websites. Whether you're needing to run on SilverStripe on another database, make use of nested URLs, or keen to take advantage of improved performance or wider unit-test coverage, there's something in this release that will help everyone who uses SilverStripe.
You can grab a copy from: http://www.silverstripe.org