Apple released three updates today through the Software Update utility and its support web site download section. Here are the descriptions provided by Apple for each update :

Apple Intermediate Codec 1.0.1 :
Delivers improved compatibility and reliability for Final Cut Express HD and iLife '05 uses. It is recommended for all users of Apple Intermediate Codec 1.0 who are using QuickTime 7.0.

DVD Player 4.6 :
DVD Player 4.6 delivers added support for DVD Studio Pro 4 authored HD DVDs. It is recommended for all users of DVD Player.
-Additional support for playing DSP 4 authored HD DVD folders from DVD discs and hard drives.
-Additional support of discs with both SD and DSP 4 authored HD content.
-Improved Global Player settings.
-Improved usage for last play and disc info dialogs

Pro Application Support 3.0 :
This update improves general user interface reliability for Apple's professional applications. It is recommended for all users of DVD Studio Pro, Final Cut Pro, Logic Pro, Logic Express, Motion and Soundtrack.

The Pro Application Support 3.0 update is also available for Mac OS X 10.3.9 here. More information on these updates may be found on Apple's support web site download section.