If Namco says its on the PSP then its on the PSP. The scan even show the button layouts which clearly says PSP on top of it The graphics do look amazing, but if you look closely, they aren't that great compare to the 360/PS3 counterpart. It will suck if they were pre-rendered, but the PSP is capable of great graphics.
As for the game, I'm sold. I'm obviously getting Groovy Tune because of Yukiho and I really like Makoto. I don't mind Takanae at all, but Miki I just don't like her that much.
Funky Note would be my second choice because it has Iori and the twins. Hibiki is pretty awesome and Yayoi is just adorable.
Honey Sound, meh. Haruka is the only one I really like from that group and Chihaya is okay for me. I just don't like Azusa and Ritsuko.
I will be getting Groovy Tune for sure and hopefully I can afford Funky Note as well.
I just hope Namco doesn't save the best songs and costumes and other cool stuff for DLC only and only gives a cheap selection of songs.