Came across this video via SpekSNK.
It's basically a video showcasing all the different characters in the game, of which of course includes some SNKP characters, and introduces the game's system/gameplay.
The game itself actually reminds me a whole lot of Super Robot Wars, particularly the battle sequences, except with boobs/girls instead of Mechs.
It seems unlikely it will be released outside of Japan due to the amount of companies involved, it actually does look quite decent though and hopefully at some point i'll try to pick up a copy of it. (Though because of Sony's stupid import laws for Europe it doesn't seem like it'll be any time soon... =_=)
It is actually possible though to buy the Mai Shiranui book from the Queen's Gate series on Playasia.
At the time of writing it is currently £16, not including shipping.