There are rumors circulating that the new version of Mac OS X 10.6 Snow Leopard has been seeded to some of the top developers for beta testing. The latest build is said to be 10A261. The prior version of Snow Leopard delivered to developers was in December (build 10A222).
According to Macity, the latest version does not seem to contain anything different but does seem to be more stable. They report:
"The interface has not been revised and currently there are only small changes in System Preferences, have been resolved a few bugs in the Finder and little else. According to the sources of Macity the impression is that this release is more reliable than those previously distributed."
Apple has said that they intend to focus on quality and performance in Snow Leopard and there have been rumors for some time saying that Apple has been tweaking the OS to achieve this. Apple has also made it clear that the OS will give exceptional support for multi-core