The most notable improvement from my point of view is tightening of the checks on the data that go and come over the wire between repositories, but it probably is and should be invisible to the end users. Many other small improvements are all over the place.
The release tarballs are found at:
and their SHA-1 checksums are:
The development cycle for the next release is expected to last for 8 weeks til the end of January, and some of the major planned topics are listed here.