The previous Beta Release was Second Life 2.2.0 (210127). The current download is 211499. It is available here: Second Life Beta Viewer Download = direct to download. For the paranoid, this is the download page: Download Second Life Viewer 2.
The main download remains Second Life 2.1.1 (208043).
The changes, release notes, for the new beta version are not up, yet. But, they will appear here: Release Notes/Second Life Release/2.2.0.