It's rumoured that tomarow (friday) there will be an update for Mac OS X.0.III to Mac OS X.0.V. I don't know why they skipped X.0.IV, I guess it's too ig of an update to increase to version numbers so little. I found @ ThinkSecret.com
Mac OS X Update Due for Friday Release
Think Secret has learned from multiple sources that Apple is planning to release another minor update to Mac OS X this Friday. If the release goes as planned, then it will probably be available under the 10.0.5 designation, skipping 10.0.4. Among other issues, speed should be improved, and two sources mentioned the possibility of DVD playback functionality with this release.