The latest Pantheon web farm update to www-dev and www-test (release tag 2012-08-20b) includes:
3 core changes
fixes to 1 snippets
changes to 2 themes

The svn logs of these changes are:

• [pantheon] Fix error messages from twitter & EventsCalendar snippets.
• [pantheon][chronos] Canary page – add webfarm snippets + EventsCalendar
• [pantheon][chronos] Updated sample site
• [Pantheon][Themes][CCUSB] Custom tabber.js file
• [Pantheon][Themes][CCUSB] New style tabs, fixes to summary styling.
• [pantheon][core] Pantheon now writes errors to error logs instead of simply eating them.
• [pantheon][core] – SiteStat.class.php modified
• [Pantheon][Online Prospectus] new PG Prospectus layouts

These updates will be rolled out to the live webfarm servers once the Clearing period is over.