Messi will STAY at Barcelona.
as good he is i think he has to stay at barca to be remembered as one of the greatest ever. Hes not as good as he used to be so i dont think he'd have huge success in EPL or german league. He'd still score 20 a season etc.
He's not the kind of player that will succeed in BPL as there he will face defenders that actually know what defending is.
BBVA has barely defenders worth mentioning beside these who play for Atletico and Real.