i personally like Ueda's solos, especially LOST &
Love in Snow. i'm thinking "Ai no Hana" will be a ballad or a mid-tempo one with some rock influences.
i think Kame's solo will be similar to 00'00'16 (Sixteen Seconds), Junno's a not-so-crazy Samurai Love Attack w/ a summer flavor, Jin's a ha-ha ~episode II~ or
Sore Zore no Omoi, Koki's will be similar to...his other solos LOL, & Maru's an upbeat song with hip-hop influences.
LOL. those are my guesses.