Update: As expected, the feature was officially announced by Valve in their New Bloom Day 3 announcement. Read at http://www.dotamt.com/new-character-phoenix-announced/
Perfect World, the game operators for Dota 2 in China have included a tidbit of information in their Bloom Festival announcement that was left out by Valve. The information explains the addition of a new game mode named Replay Takeover.
Perfect World jumped the gun & have referenced a new “Replay Takeover” mode which allows for 10 players to continue playing from any replay.
— Matthew Bailey (@Cyborgmatt) January 28, 2014
As can be derived from it’s title, the new game mode will allow 10 players to load a replay and choose a timestamp from which they can continue to play from. While details are somewhat scarce, we do know that the feature will only work for replays saved after the new Bloom Festival patch is out.
It is still unclear how exactly this will be implemented, but already one can think of several uses for it. For one, I think it will be useful for team training a specific scenario which might be hard to recreate such as unique initiations and counter-initiations. Further details should be announced tonight in the Bloom Festival Day 3 official blog post by Valve.