The release includes 27 bug fixes and feature enhancements. The scope of this release was primarily focused on improving the current feature set in terms of usability, reliability and support for logging complex objects. You can find the changelog here.
After installing the FirePHP 0.2 extension you will be directed to the Install page after your next Firefox restart. On this page you need to download the updated FirePHPCore library. Next you can visit the Learn page for information on how to get started with FirePHP. Finally refer to the Usage page as a reference for all supported features.
Some of the updates included in the release are for enhanced object logging, the addition of file and line information, full UTF-8 and Latin-1 support and an enhanced variable display in the console. Head over to the FirePHP.org website to get the latest version.