There have been stated countless times how similar Bleach arcs are. I want to look into it once more, and try to predict flow of the story.
Now, Bleach has 4 major arcs (named are made up by me, so sorry for them being lame):
1) Karakura Shinigami
2) Rescue from the Heavens
4) Rescue the Princess
As we seen, the pattern is: one Earth arc followed by one Another Dimension arc.
(Main Hero path) Earth ar˝ consist on New enemy revelation (also Mini-boss and The Boss of next arc is seen coming to Earth), New power revelation, Training to harness this power and Girl kidnapping by Enemise (more priecely, Girl going to Another Dimension with them on her own "free" will to save the friends). Ends with rescue team going to AD.
Another Dimension arc is rescue arc, consists on: Arrval, Meeting the Support, fight with Guardian, Entering Enemy Lair, fighting microboss, Mini-boss, Mid-Boss, Power-up, Allying with Mid-Boss, and Mid-Boss, Rescue of the damsel, Fighting The Boss, Revelation of Bleach's Final Villian's plans, and return to Earth. Also, in final fight, glimpse of new power is shown.
Now lets see:
Karakura Shinigami arc: New Enemy -- Shinigami. New power -- Shinigami power. Damsel -- Rukia. Training -- Urahara. Renji and Byakya as next arc bosses
Rescue from the Heavens arc: Location -- Soul Society. Support -- Shiba Family, Enemy Lair -- Seireitei, Guardian -- Jiroubo, microBoss -- Ikkaku, Mini-Boss -- Renji, Mid-boss -- Ken-chan, Power-up -- Bankai, Rukia saved from execution, The Boss -- Byakya. Aizen's plans revealed, New power -- Inner Hollow appeared.
Hybrides arc: New enemy -- Arrancar, New power -- Vaizard power, Training -- Vaizard, Damsel -- Orihime. Grimmjow and Ulquorra as next arc bosses.
Rescue the Princessarc: Location -- Hueco Mundo, Support -- Great Desert Bros, Guardian -- Big Sand Thingie, Lair -- Las Noches, microBoss -- Dordoni, Mini-Boss -- Grimmjow. └fterward is yet to see. Speculating: Mid-Boss -- Noitora, Power-up -- dunno, Resurrecion?, Orihime saved after the confrontation with: The Boss -- Ulq. Aizen's plan -- dunno, Hime unsealing Orb of Distortion?, New power -- dunno, some Perfect Hybride power? Royal Blood power? ^_^
And we will see Grimm alive and facing Ulq (and falling... Still, two levels is great difference), and Noi alive and facing (dunno, Tousen again? Halibel?)
Next, if we are to assume, that next two arcs are Winter War and Assault on King, then:
Winter War arc: New enemies -- Vasto Lorde Arrancar? New power -- Perfect Hybride? Or Royal Blood power? then Training is with Isshin ^__^ Damsel -- Tatsuki? ^_~
Assault on the King arc: Location -- Kings' Dimension, Lair -- King's Palace, enything else is unpredictible.