According to sources Apple has released a Safari seed to developers that promises a "significant" amount of bug and performance fixes regarding the following areas:
- large plaintext pastes
- photo uploading to auction websites
- Handling of "unsafe" Javascript
- Writing direction shortcuts
The seed build numbers are 9B4021 for Leopard, 8S4021 for Tiger, and 31A15 for Windows.
Evidence has recently been surfacing that Apple is planning to bring a host of performance improvements to Safari. An earlier Safari beta appears to have incorporated recent rendering improvements to WebKit.