About Yamato Genrusai (Captain Commander). Interestingly he hasn't really had a chance to cut loose and wreck havoc in Bleach although we have had some tid bits of his awesomeness. During the Aizen arc, Aizen sealed his sword Riyu Jin Jaka. I wonder now if the same thing won't continue to happen to him.
Obviously the Fuhrer (Buckbeard) is quite aware of Yammaji's power, but the fact that he so brazenly wants to attack SS against so many captains makes one wonder that he must have a method of neutralizing Yammaji and the others beyond merely sealing Bankai, as I recall, the only captains who actually used Bankai vs Aizen were Soifon, Toushiro, Byakuya, and Dog face guy (lol can't think of his name atm). Point is that most Captains fight without releasing their Bankais, so sealing Bankai would not be much of an advantage.
Other musings are:-
Whether Yammato Genrusai will actually survive the end of this arc. As Aizen noted, he has been the history of SS itself. Genrusai has made many mistakes, and exterminating (or is it Not exterminating) the Quincy was one of them.
Whether squad zero will intervene
Whether Aizen would be paroled
Whether Ichigo will remain on Earth after the fight or join SS as a Captain
Whether Harribel will be rescued, and whether SS and Hueco mundo will declare a truce and establish diplomatic relations..