Question

What are all the new features included in ORAS which were not there in Ruby, Sapphire and Emerald?

Answer 1

Well, there is Soaring, Mega Evolutions, Legendary Pokemon, Delta Episode, Shiny Beldum event, Mirage Spots, DexNav, BuzzNav, AreaNav, PSS, Primal Groudon/Kyogre, Battle Resort, References to other regions, Extra Cave in Victory Road, Secret Meadow, Secret Islet, Secret Shore, Move Tutors, and I think that's it.

Hope I helped!