The first is the Mac OS X 10.5.2 (9C7) update which lists fixes to 76 distinct issues. Bug fixes range from memory leaks, various printing issues, SMB support and more. It is possible that Mac OS X 10.5.2 will be ready for final release at MacWorld.
Apple also seeded Java SE 6 Preview 8 for Leopard. It is an implementation of Sun's Java SE 6 for Mac OS X 10.5 (Leopard) and includes Java SE 6 version 1.6.0_01. This latest seed requires a 64-bit capable Intel-powered Mac and is described as having received only limited testing thus far.