I think it should stay Aeris. That way people will pronounce it Aeris. And we won't have any of those "What?! Its pronounced THIS??" crap going on like we do with Tidus and apparently I've been mispronouncing Cecil's name all these years. Screw that crap. Aerith is pronounced as Aeris. Spell it how it sounds :(

On the other hand if it were pronounced the way its spelled. Aerith has a softer friendlier feel to it than Aeris. Too bad that's irrelevant. Otherwise I might be okay with the inevitable change

It'll be Aerith. Regardless of opinions