User blog comment:Xilinoc/Ch. 655 - THE MIRACLE/@comment-24769684-20151210165435/@comment-5398287-20151212184532

Apparently, Urahara was meant to be the main antagonist of the series until Kubo decided it would be more interesting if Aizen were instead (Aizen was actually gonna stay dead and stuff), hence Urahara's shady behavior in the beginning. However, at this stage in the game I can't see him turning bad, especially given his speech on how important the Soul King's existence is, which would put him firmly against Yhwach.