The upcoming 7.3.2 is a follow-up update with security improvements; Google Search module rewritten for the new API; new alerts (message sent in Shoutbox and Simple Messenger, Greeting sent, Album add/edit/delete, Video/Photo/Sound/File edit) and a number of minor fixes and enhancements. As of this Beta there are 54 total changes in total.
Full list of changes:
This beta is for testing and development use only. It is not upgradable and you can not apply it on an existing site. Upgrade script will be available with the Final Release.
We encourage module developers and anyone willing to help to download, try and report any inconsistencies. It is a good idea to check your modules compatibility ahead of the release.