[Unsal Korkmaz]

bbPress 2.4 introduces hierarchical replies, allowing you to pick between paginated topics or a hierarchy (similar to WordPress’s comments.)

FirmaSite is already supporting bbPress with hierarchical replies! Its free and approved by official theme reviewers in wordpress.org

Example Forum: http://demo.theme.firmasite.com/forums/
Example Threaded Topic: http://demo.theme.firmasite.com/forums/topic/example-threaded-topic/

You can read user’s reviews!

[John James Jacoby]

The approach in bbPress core is slightly different than what @jmdodd’s plugin originally did. You’ll want to test and let us know how it fares.

[Unsal Korkmaz]

bbPress 2.4 released! Now you can easily use it with hierarchical replies