Apple posted Safari 5.0 for 10.5.8 and 10.6, and Safari 4.1 for 10.4.11 yesterday and above is a link to the full patch list (and it's quite extensive)
The things patched in this update are below:
- ColorSync (Windows versions only)
- Handling of PDF files
- Arbitrary code execution (Windows only)
- Webkit (tons of updates here including the infamous wushi exploits from team509, also lots of mentions of Chris Evans and Mark Dowd. Nice work guys.)
Check the full list at the above URL for complete details.