Shin'en announced Nano Assault way back in April of 2011. Since that point, all I've been able to surmise is that it's some sort of multi-directional shooter, and any attempts to learn more via in-game footage has been in vain, as most of it is badly recorded E3 footage.
I know a lot of people are fatigued with these type of games, but Shin'en has a long history of high quality shooters, so I'm willing to give them the benefit of the doubt. Not only did they develop the well-loved Nanostray and Nanostray 2 on the DS, they also developed Iridion 3D and Iridion 2 for the Game Boy Advance. I have fears that the game won't be as successful as it should be, but that happens to a lot of good games, unfortunately.
Nano Assault is set to release November 22, 2011 for $29.99, and more info about the title can be found at it's official website. Anyone with any passing interest should give it a try, and honestly, now that I've seen the trailer, I'm fairly sure that the game is going to be pretty darn fun.