That's too fast, Brand New World didn't start all that long ago did it? That's only about 4-5 episodes away… I would've expected the song to change until mid to late in
! Luffy and Lucci's fight. And Brand New World is so catchy too. Maybe the new one will be more jumpy and fit in longer and more visual scenes of the CP9 fights.
Possibly also featuring whomever it will be as the next crew member. I know Franky's already in the Brand New World but maybe the manga would have revealed the 8th member will be Franky (not saying he will, not saying he won't) so the theme song will do the same (like when Robin joined, the theme song already featured her before the anime actually showed it right?).
The 10/15 date is advertising episode 281, which'll be Nami's flashback. The bottom half of the One Piece box there is the opening announcement. ^^
Yeah, the second half of the title says "Nami's World Map" I think.