In today's Nintendo Direct video for E3, Nintendo announced there is a new Super Smash Brothers coming. The full title is now just 'Super Smash Brothers' (nothing like Brawl, Melee, etc. added on), and the game will be coming to both the 3DS and Wii U.
The video Nintendo presented showed many of the series common characters, but also introduced 2 new characters. The first is Villager from Animal Crossing, who will have attacks involving an Axe, a balloon hat, and other Animal Crossing themed items.
The 2nd character is MEGA MAN, and he will have not just his blaster, but also the powers of bosses from games past, although it's unclear how those abilities might be enabled.
Super Smash Brothers for 3DS and Wii U will see a release in 2014.
We'll update this story as soon as we can provide the trailer from the announcement today. UPDATE: First trailer below (minus Mega Man footage, still looking for a suitable video).
UPDATE 2: Found a full video (GameTrailers comes through!).
Super Smash Brothers Game Announce video