Theory:
Alpha Sapphire/Omega Ruby are sequels, not remakes

Firstly:
The pic related is from the trailer.
It says 'new'.
Not 'revisited' or some such.

Second:
Mega evolution was confirmed thus far to only exist in Kalos.
I doubt that GameFreak would just dump the feature for future games.
For megas to exist in Hoenn, it'd have to be the future.

Third:
Kyogre and Groudon have minor design changes:
The patterns covering their bodies have been altered.

I think this is a sequel, and that they're gonna go all "Kyogre and Groudon are at it again."

This is just what I've gathered from watching the trailer a few times over.

Discuss.