"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
Security Update 2007-009 for Mac OS X 10.4.11 and 10.5.1 [Updated]
Mac OS X 10.5.1: Core Foundation, CUPS, Flash Player Plug-in, Launch Services, perl, python, Quick Look, ruby, Safari, Samba, Shockwave Plug-in, Spin Tracer
Mac OS X 10.4.11: Address Book, CUPS, ColorSync, Core Foundation, Desktop Services, Flash Player Plug-in, gnutar, iChat, IO Storage Family, Launch Services, Mail, perl, python, ruby, Samba, Safari, Shockwave Plug-in, SMB, Spotlight, tcpdump, XQuery
A detailed breakdown of the security fixes is