http://us.battle.net/d3/en/blog/9382478/developer-journal-multiplayer-improvements-4-2-2013- 10% more XP per extra player in the game
- "matchmaking tag" for Public Games
- Monsters currently gain 70% extra health per additional player in the game. This is being reduced from 70% to 50%.
- Archon duration will also be extended by assists
- Identify All
https://bnetcmsus-a.akamaihd.net/cms/content_folder_media/XQ2FFIV4YJJ21364935694772.jpg
- Combat Alerts
Starting in 1.0.8, when a player deals damage to or takes damage from an Elite pack or Treasure Goblin for the first time, a notification will be sent out to the entire party to let your teammates know what you've found.
etc