Well, we told you it was coming... :-) Seriously though, Apple has finally released the Mac OS X v10.0.4 upgrade. Reach it via the normal Software Updates app in the "Control Panel."
Relevant links (Apple TIL items):
- Mac OS X (10.0.4) Update Information and Software
- Mac OS X (10.0.4) Combined Update Information and Software
- Mac OS X (10.0.4) Combined Update Information and Software
- Mac OS X 10.0: 10.0.4 Update and Before You Install Information
- Mac OS X Server 10.0: About This Mac Says 10.0.3 Even Though 10.0.4 Is Installed