Kubo already tweeted, he will do another 2 arcs, one is 6-8 months long, another will be (hopefully) 2-3 years arc.

My prediction is, Aizen wishes to the hogyoku that it turns him like how Ichigo was,
stripped from his Zanpakuto powers, but be one with his Zanpakuto
Aizen is gonna bring all sorts of crazy immortals from the underground prison back with him, I put my money on it.

I understand how ppl can get so impatient, with Kubo's pace.
If you read weekly, it seems boring and dragged out, but as a tankobon, its really a great one.

You see, unlike other mangakas, Kubo wants to please his Western audience too.
He tries to incorporate western comics into his manga, hence the flashy artworks when drawing fights.
Cos if you read western comics, its really this way, not so much words, but the pictures explains a lot, and the rest is taken by imagination.

I think theres nothing wrong with his plot, but rather the pacing, in which the Jump is, which is on weekly basis.
Because of the pacing which cant keep up with the plot, the elements seems redundant, cos ppl tends to sum it all up without taking it all in
while in truth, they are not.

I read marvel comics a lot, I can see the elements he wants to bring in into japanese manga.
I respect him for this, I think he did a great job of a manga+comic fusion.
If you feel that Bleach suck in any way, just try and re-read it once, as a volume.Really have a different feel to it, perfectly weaved.