Delays in the Subversion 1.5 release occurred because the implementation of the merge tracking raised a number of issues (previously considered to be unimportant) which needed to be addressed.

The Subversion 1.5 release will implement major new features including: 

• Merge Tracking
• Sparse checkouts
• Changelist support
• Copy/move-related improvements
• Interactive conflict resolution
• WebDAV transparent write-through proxy
• Cyrus SASL support for ra_svn and svnserve
• Cancellation improvements
• Relative and peg URLs in svn:externals
• FSFS sharing

These improvements will enhance the Subversion user experience by allowing more control over working copies, giving faster responses from the server, and allowing to branch and merge in a far more efficient manner. On the client side the implementation of Interactive conflict resolution will improve user experience when faced with conflicts. Other developments of note include the WebDAV transparent write-through proxy which will give subversion a native (if not slightly limited) multi-site capability that was lacking from previous versions.

New features will be further enhanced in subsequent releases of 1.5.x. General consensus within the Subversion development community is that the initial 1.5 release has taken too long (although it was important to make sure that the release was both correct and stable). The next major release (1.6) should not suffer from similar delays, in fact development is already underway in parallel with 1.5.