According to statements released by DeNA and Nintendo, this means that the big N will create new games specifically for smartphones.
The alliance is intended to complement Nintendo's dedicated video game systems business and extend Nintendo's reach into the vast market of smart device users worldwide. Under the alliance, DeNA will also be able to strengthen its gaming business at a global scale by leveraging Nintendo's IP. To ensure the quality of game experience that consumers expect from this alliance of Nintendo and DeNA, only new original games optimized for smart device functionality will be created, rather than porting games created specifically for the Wii U home console or the Nintendo 3DS portable system.
But wait, it gets better. As part of the agreement, this may also lead to Nintendo IPs showing up on the PC in some form.
Nintendo and DeNA expect to develop a new core system compatible with a variety of devices including PCs, smartphones and tablets as well as Nintendo's dedicated video game systems, and are to jointly develop a membership service utilizing this system, with a launch targeted for the fall of 2015. The companies expect to further enhance their customer relationships through the membership service.
Obviously, this is no guarantee that we'll see something like a new main entry for Super Mario or Metroid game on our PCs but... maybe.
I don't want a Nintendo-themed War Of Heroes game... I got bored so damned fast because of how little substance Marvel War of Heroes had, and how anti-trading that game is, despite being a trading card game.