As an author, if someone votes on your post in the first 30 minutes, you receive a portion of the curation rewards in addition to your author rewards. (More details are in the FAQ if you are interested.)
With HF 20, instead of those going to the author, they will just be left in the rewards pool. This keeps more rewards in the rewards pool to be awarded to other authors and curators.
Thanks @timcliff !
Just one more clarification - the duration rewards "lost" from voting early on a specific post will NOT go to that specific post's voters but to all of the curators of all posts in steem? It makes it worth much less to the curators of the specific post if it's true...
It is just left in the rewards pool, to be distributed to other authors and curators on other posts.