Magento version 1.2.0.1 is now available for download and upgrade. This version includes issue resolutions for Magento version 1.2.0 as listed in the release notes.

Note: We do NOT recommend upgrading a production installation of Magento directly. Please backup database and all files before upgrading. Please make sure to check file permission before trying to upgrade through your Magento Connect Manager.

Read more at Magento Homepage