This is a Stability Release, which means it does not have any new features, it only contains fixes, to bugs discovered in the 1.0.1 release.
1.0.2 is available as a Full Package, which contains all Joomla! files and a Patch Package which contains only the files that have been changed by the Stability work conducted.
1.0.2 Version Information
To update from Joomla! 1.0.1, all you have to do is simply overwrite files from the 1.0.1 to 1.0.2 Patch Package.
To update from Joomla! 1.0.0, all you have to do is simply overwrite files from the 1.0.0 to 1.0.2 Patch Package.
For those converting from Mambo please read these Migration instructions.
You need to download the Joomla 1.0.2 Full package.
Thank you to the community for their continued assistance in helping us make Joomla 1.0.x more stable and our apologies for missing the target release time again.
Rey Gigataras [stingrey]
Joomla! Software Coding and Design
Stability Team Leader