Sites: Comments in Sites now have new features that are similar to the ones available for comments in Google documents, spreadsheets and presentations. Users can now +mention others, get new comment notifications via email and respond to comments via email.

The following features are intended for release to these domains on October 8th:
No new features to announce.

Release track:

Editions included:
Google Apps, Google Apps for Business, Government and Education

For more information:
Get these product update alerts by email
Subscribe to the RSS feed of these updates