Along with the confirmation of a second season Anime show of Suzumiya Haruhi, the latest August issue of Newtype also reveals details about the upcoming PSP game too.
Named "Suzumiya Haruhi no Yakusoku", it will be an ADV game as stated before. As you walk around the campus and come across events, you get to play some mini games. Nothing about whether the story will be the same as the show or not but, it will feature full voice acting played by the very same Anime cast.
The "new element" mentioned before will be the "Motion Portrait" system. Apparently character expressions will change in real time which may mean you won't see the usual slideshow "tachie" portraits that you get in ADVs.
I'm actually wondering if this system is just going to be similar to the way characters are animated in Ace Attorney, switching from one set of animation frames to another or, will it really have smooth transitions between each expression. I guess we'll see.