When I saw at first in the Trailer of end of BW, the cameo of Iris vs Clair, Iris and Gible and the Brock and Cilan one, I had the feeling that this two episodes would be two separate specials for each Iris and Cilan.
Maybe, in the last episode of BW, BW142 whichs title we learned today, Iris decides to land to Johto o get more excperience under Clair, while Cilan maybe decides to turn home, although for me it doesn't make really much sense, and by the way he meets Brock.
Assuming that we get only two episodes in Kanto, and only one I guess in Pallet Town, if all these things would happen would be a mess up, and we would get an overrushed-20 min episode. This is the only reason why I would like the "Brock return" episode as a special, and so for the Iris's one too.
Regarding to these "Episode", I would like to see Brock in action, using his Pokemon in battle, and introducing a newly-evolved pokemon of his, maybe Geodude or Marshtomp.
And why not catch a new Pokemon.(I doubt this, though).
I really hope for a well-treated episode.