Reddit have tested this feature for a while allowing only Reddit employees to create these live streams and authorize trusted “reporters” to contribute.
But now it’s open for all, , anyone can create a Reddit Live blog and submit their ongoing threads to a dedicated subreddit. This would have been an amazing feature if it was revealed before the world cup! Especially that it allow users to embed tweets, videos etc …
The difference is, that unlike traditional Reddit posts, these threads will update in your browser automatically and in real-time.
To make a live thread, need to start here: http://www.reddit.com/live
example of the live thread: