I'm looking forward to the combination of these pokemon appearing:
- Simisage, Simipour, Simisear: All three in a triple battle with Ash.
- All of Marshal's pokemon appearing: Fighting type tournament with Ash's new Pignite and Scraggy and Trip's Gurdurr?
- Bisharp, Zweilous, Hydreigon: Iris and Georgia episode in which we learn Georgia's reason for wanting to bash dragons so much.
I still wonder where Swadloon will evolve though, it's in the february calender, and all pokemon from the march calender appear in these three episodes (BW72/74), so that would only leave BW71: The Celestial Tower episode, even when that is in March already.
Leavanny and Ducklett are the last to appear from that calender, and I think we can see them in BW71. With Ducklett being random, but Leavanny of course not.