The game is now available for pre-order via the game's website. Unless some major show stoppers crop up the full game should be out within a couple of weeks.
The OST for Danmaku Unlimited 2 and Storm Strikers have also been announced! It'll be on sale at Comiket 84 on August 12th and will also be available on iTunes! In the time being you can head over to the website and preview the soundtracks.