Finns i Software Update. Apple:

What's New in Final Cut Pro 4.1

Final Cut Pro 4.1 addresses performance and reliability issues in Final Cut Pro 4. These include the following fixes, enhancements, and new features:
XML Interchange format is supported.
Create Support Profile has been added to the Help Menu (for improved AppleCare support).
Reconnecting media to subclips is improved.
Batch capturing 32 kHz audio is accurate.
Working with clips containing speed effects has been improved.
Various issues with ripple delete have been eliminated.
Instances of match frame not working have been resolved.
Trim Edit window response time has been improved.
EDL import/export has been improved.
Autosave now functions as expected.
Project files now maintain an accurate file size.

Final Cut Pro 4.1 is strongly recommended for all users of Final Cut Pro 4 or later.

Även Cinema Tools, Compressor och LiveType har fått uppdateringar.