I KNEW IT!! XD
Sometimes I visit official Gamestop sites and there they wrote when videogame will be available online and in their shops...even before the Nintendo announcemen (Should never wait for Nintendo if I am very impatient, because in those sites you can find the releas date before its announcements! XD).
Then, also trough Gamestop sites I saw when Mario and Luigi: Bowser's inside History is coming out in my Country (Italy-UE: in Italy the title is going to be "Viaggio al Centro di Bowser"- it means "Travel into the Centre of Bowser". Pretty different from your one... ;p). The 9th October...later than the American release date... :( But I really can't wait! That game inspires me so much, as well as New Super Mario Bros Wii!! *-*