Here are the items/Pokémon you can transfer from the ORAS Demo to ORAS:
Steelix and Steelixite - Complete the first adventure (Japanese region)
Glalie and Glalitite - Complete the first adventure (Korean, PAL, and American regions)
Poké Ball ×10 - Complete three adventures
Heal Ball ×10 - Complete five adventures
Heart Scale ×5 - Complete ten adventures
Nugget - Complete Strange Secret Mission
Sceptile, Blaziken and Swampert, along with their respective Mega Stone unfortunately can't be transferred from the ORAS Demo to ORAS.