Google Docs has always been an easy way to collaborate over a documents because many users can access the documents at the same time. But today, Google is stepping up the collaboration factor with more structured, threaded discussions. While previously users could add comments in Google Documents, today, Google is upgrading these comments to an actual discussions-like format within the document.

Comments are easier to see and visualize with timestamps and profile pictures from the Google account of the commenter. One of the more significant changes is that if comments are not integrated with your Gmail inbox. So when a document you’ve created is commented on, you’ll receive an email with the comment.

You can also @mention someone (with their gmail address) to add them to a discussion, and he or she will receive a notification email with the text of the comment. Users can reply within the email or click to the comment in the actual document and reply within Google Docs (Docs users can also mute the email notifications feature).

Within Google Docs, discussions are located to the right of the document and are separated by thread and topic. If you’d like to remove comments from a document but want to save them for later, you can “resolve” a discussion thread. The thread will be removed from the document but can be accessed via the discussions button at the top of any document. That way users can keep a record of all discussions made around a document.

As Google Docs Product Manager Scott Johnson tells us, existing comments within Google docs doesn’t work from a discussions and sharing comments over email on a doc doesn’t work from a collaboration standpoint. This release helps solve that problem, he says.

Like with many products in the Google family, Google employees have been using this next-generation commenting system for several months and the response has been positive around adding structure and email integration to discussions in documents. It seems like a useful addition to the product, and one that definitely makes docs more collaborative.

Discussions will be available in the next few days to all users with personal Google Accounts as well as to Google Apps customers on the Rapid Release track. Improved comments are only available in new documents for now.