So basically Orange Islands part 2 but with Iris and Cilan instead?
That seems exciting. I really hope it's a bit more exciting than the Orange Island saga was for me. I was expecting some filler saga/island to take place until the X and Y saga starts. Some page on Facebook I look at posted some more info. I know it's hard to confirm things on but checking Serebii, it's legit. It's info on some of the episodes.
On May 30th, they visit the Mutoro Island where Profesor Oak goes against the Pokémon Rotom, with Professor Oak apparently capturing one.
June 26th is labelled "Making a Wish to Jirachi! Seven Days of Miracles" and marks Jirachi's first TV appearance. It is set on Ookina Island.
In July, there will be an episode which is currently labelled Mysterious Treasure! Uninhabited Island Adventure! where Eevee and friends will appear on an uninhabited island, Yashi Island.
Oshawott's Farewell sounds like he'll be leaving Ash. Or be in a situation where he choose to either stay with Ash or to stay on an island full of Oshwott/ Dewott/ Samurott like what Bulbasaur did in Bulbasaur's Mysterious Garden. Alot of these episodes look like they're gonna be good. Especially the Jirachi one. I hope there's some tournament like the ones during the Orange saga or maybe a Don tournament.
Edit: Also hope for some Gen 6 Pokemon to after a la Tracey's Marill.