i've been thinking about it, and came up with only one conclusion. he didn't release his bankai form until now, because if everyone in soul society knew he had a bankai, he'd probably get recommendations to try out for the captain slot, but probably didn't want to, because he wanted to be loyal and stay near his captain. as weird and random that may sound.

anyways, the episode was pretty awesome. the concentration on the fight and the fight itself was crazily done. ikkaku has one huge ass bankai, though.

as for next weeks episode, it looks like a flash back which i'm not fond of, but then again, i'm probably wrong and looked at it the wrong way.