I don't expect having any news about DOA6 before a long time. I guess there will be a new ninja gaiden before (announcement: E3 2014; launch: september 2015... DOA6: announcement: E3 2015 or later? lauch: September 2016 or later?).
What I would like to see (All my ideas!):
-> Beautiful graphics, with fine textures, for both characters and stages. Why not the most beautiful game at its launch? The game of which press will say "The game that really shows what XBOX One and PS4 can do".
A lot of complexe (no more square!), interactive, beautiful and colourful multi-tiered stages. Only multi-tiered stages, with an "only one floor" option for tag. A lot of japanese theme and nature theme stages. Each one having a powerblow special dangerzone. The come back of objects, inside stages, where we can jump over (DOA4).
More physic details for characters: improvement of sweat effects, wet effects, ripped clothing (thank you Spellbound for the idea!)
More physic details for stages, with photorealistic graphics: reflection in water, snow effects, etc.
-> No more guests, more new fighters (2 girls, 2 boys) and a new boss.
-> Original mini-games: - Xtreme beach games, to unlock a lot of accessories (glasses, necklaces, haircut...)
- A stage creation option.
- Mini-games with little challenges: For exemple, the only way to win is to ring out the opponent, etc.
-> An improvement of the gameplay with more guaranteed damages, more unholdable stun and no more slow escape. A special way to finish a combo where you can choose if you want (or not) that your opponent interacts with the stage.