Here is some awesome news.
Inti Creates revealed at Anime Expo today., that Shovel Knight and Shantae are joining Blaster Master Zero as new playable EX characters.
Shantae will be available between July 6 and July 19 for free. Shovel Knight will start between August 5 and August 16. After these periods, the characters will cost $1.99 / €1.99 as with all DLC characters.