Here's the trailer for DeDeDe's Drum Dash Z. (Official website)
Kirby Fighters Z : some pics from 4Gamer.net!
Kirby Fighters Z
-No online (download/local play only)
-Same 10 power ups as TD
-Bell & Beetle power ups available only if you have Triple Deluxe (and have Streetpass for the game enabled)
-Same deal for the Waddledee Train stage
-Single player mode, boss battles
-Beat the mode to unlock cooler looking hats
-Beat the mode on the hardest difficulty to unlock Shadow Kirby as playable
-Team battles. Able to share items with team members by 'kissing' them.
-5 new stages
Dedede's Drum Dash
-7 new stages, plus 7 unlockable 'ura' stages
-Some drums will flip to a beat, revealing spikes on the under side
-Numbered coins which give a bonus when collected in order
-Healing rings to revive health
-Symbols make an appearance, stricking them will reveal a Musical Note Coin
-Some other new things in stages
-Unlock masks to wear while playing
-Kirby, Waddledee and Meta Knight masks exclusive to those who have Triple Deluxe and Streetpass for that game turned on.
Kirby Fighters Z comes out on July 23 in Japan, for 500 Yens.
DeDeDe's Drum Dash Z comes out on July 23 in Japan, for 750 Yens.
Thanks StreetsAhead for some of the info.