Azure Striker Gunvolt 2 is indeed happening. The good word comes from the official Gunvolt Twitter account following the opening of Inti Creates' FanFesta 2105 event. The game's website has gone live but it's a bit topsy-turvy at the moment due to heavy traffic.
In the meantime, Famitsu has a first look at a brand new character (above). Gunvolt 2 will hit the Nintendo 3DS later this year.