Alright, I've compiled a list of some things we basically know are coming but haven't been announced and thus are probably likely to be announced here, let me know if I missed something.
- Boss Battle Mode
- Tourney Mode
- Yellow Team
- Event Match
- Coin Battle
- Special Smash
- 8 Player Smash
- Special Orders/Master Orders/Crazy Orders
- Ticket Selection?
- Smash World
- Official Tourney?
- Stage Builder
- Temple Stage
- Great Cave Offensive Stage
- Metal Face (in some way)
- Ridley (in some way)
- More with Amiibos?
- 3DS/Wii U Connectivity
Not even close to 50, although these may be most of the big things...
Was boss battle mode revealed in those audio files?