"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Mac OS X Intel Build 8F1111
According to the rumor site, Apple has distributed Mac OS X 10.4.3 Intel Build 8F1111. The update is said to provide additional printer drivers, native version of Quicktime 7.0.4 and other improvements.
One component that saw significant updates included Rosetta - Apple's PowerPC emulation layer for the Intel Macs.
Rosetta included improved support for OpenGL as well as support for AltiVec. This report corroborates a previous Page 2 report claiming the same.
Update: OSx86Project claims that Appleinsider's article is entirely based on their original report. Though Appleinsider does cite both "sources and reports on the Internet".