Logos 4.2a Beta 7 (v4.21.5.0333) will be available for testing today.
When it is available you can upgrade to Beta 7 by using the "Update Now" command if you’ve switched to the beta channel before, or the "Set Update Channel to Beta" command if you're on a stable version (such as 4.2 SR-2). To install Beta 7 from scratch, see the notes and download link at http://community.logos.com/forums/t/8883.aspx.
For Release Notes, see: http://wiki.logos.com/Logos_4.2a_Beta_7.