Okay, so here's what I want to see, incorporating the majority of BW, so that you guys get a timeline here:
BW1 - Start of Best Wishes
BW5/6 - Striaton Gym
BW15/16 - Nacrene Gym
BW25 - Castelia Gym
BW41 - Nimbasa Gym
BW55 - Driftveil Gym
BW75 - Mistralton Gym
BW90 - Icirrus Gym
- A lot of Team Plasma stuff in between..
BW115/6 - Opelucid Gym (arc one, with Drayden still accepting the challenge)
- A lot of training stuff in between, particularly heavy focus on Iris' training.
BW125 - Opelucid Gym (arc two, Drayden is challenged by Iris, and he grants her the option of fighting as the gymleader against Ash)
BW127 - Opelucid Gym - Ash vs. Iris.
- Then a whole lot of training with the reserves, and a bit of Plasma activity
BW140 - Pokemon League Starts!!!
BW153 - Pokemon League Finals! Ash vs. N! Ash LOSES! Mostly because N spams Kyurem in his face..
BW154 - Ash has to start dealing with what N has done, and more importantly, what he is planning. This can be seen as a 'filler' part, as the League is already over, but it could involve the Seven Sage (a battle with one around every 4th episode, excluding Ghetsis. That will be a special treat after N is defeated), Looker and finally it would all end with a Ash vs. N rematch.
BW185: Ash vs. N rematch: Ash goes Narutalk-no Jutsu after defeating Kyurem.
BW189: Ash and N vs. Ghetsis: Ash and N double team Ghetsis.
BW190: Iris goes back to Opelucid City, Cilan marries Darach.
BW191: Ash goes back to Nuvema Town and says goodbye to Trip, Juniper and Unova.
Basta...
So yeah, I can see the League being earlier then the finale of the series. The set up is sort of similar to how Hoenn had its league 120 episodes in, and still lasted longer then that.
With more pokemon being caught, I think it's necessary to place the League further back into the series so that all can get decent development. The story arc with N and Team Plasma can continue afterwards with N already being the champion, but for some reason can't accomplish his goal. Fighting the Sages shouldn't take too long, heck Trip can even help if the writers feel as if they're running out of time.
I just can't help but feel that the N storyline is just too good to ditch, and that the games way of handling it would be too brash for the animé. This way, with an Ash vs. N rematch after the league, the writers would have an oppurtunity to keep the original storyline, and have Ash beat a champion in the same season. However due to the League getting such an important part in this then ongoing storyline, I can see it getting a shipload of episodes, possibly getting the few the Grand Festival got in Sinnoh attached to it, so
8 -> Sinnoh League
4 -> Sinnoh Grand Festival
_______________________++
12 -> Unova League?
Episode 1 -> Opening, two one on one preliminary battles (and a few still screens ala Johto, aka the battles that only hate (our Johto-troll) had remembered)
Episode 2 -> Top 128: 3 on 3 - Langley
Episode 3 -> Top 64: 3 on 3 - Random
Episode 4 -> Top 32: Triple Battle - Random
Episode 5 -> Top 16: Triple Battle - Cheren (although I think that Trip is his replacement, they're basically identical)
Episode 6 -> Top 8: Full Battle - Bianca
Episode 7 -> Top 8: Full Battle - Bianca
Episode 8 -> Top 4: Full Battle - Trip
Episode 9 -> Top 4: Full Battle - Trip
Episode 10 -> Top 4: Full Battle - Trip
Episode 11 -> Finale: Full Battle - N
Episode 12 -> Finale: Full Battle Ending with N triomphant.