User blog comment:Salubri/Aizen, Yamamoto and Wonderweiss/@comment-1248963-20100227023330

I'd think the short arc would be some sort of TBtP, a past arc I mean, that will, as Tinni says, set up things for the long arc. But that's my own theory.

Most people believe it's going to be about Isshin, since Tite Kubo said a long time ago that he wanted to write about Isshin's history, but he might've changed his idea. Another theory is that it's related to Yachiru, or rather, Yachiru's namesake, you know, the only one Kenpachi ever admired, but nothing had been confirmed.

The two following arcs will depend on Aizen's fate for the end of the Arrancar arc. If he lives or dies, if he succeeds in creating the Key of retreats to Hueco Mundo. As far as I knew, Kubo hasn't planned the end for Bleach, last I heard "he had a lot of stories he wanted to tell" (that's an old interview though). We'll have to wait 'til June to see how this Arc ends, then we can start to predict where the new arcs are directing to.