Pokemon following you around like in Yellow,Hg,SS: Heck no, that feature was just annoying and IMO was a blatant symbol of your Pokemon's disobedience.
Berry Trees Back: No, too much of a hassle to keep watering them.
New Battle system (6 on 6, etc.): Heck no, the screen is cluttered as it is with three Pokemon there.
Multiple Regions: No, no, and NO!
Battle Frontier return: Don't like the battling style there, but it's gotta be better than the monstrosity called the world tournament.
New Starter types: No, but I do support not giving the fire starter another fighting subtype.
Dark type Gym Leader: Eh, doesn't really matter to me. Either way I'll cream them.
Tournament instead of elite four: No, don't mess with a proven formula.
Return of team rocket: No, they have no reason to return.
New eeveelutions: Heck no, there's plenty as it is. I wouldn't ever use any of them besides Jolteon and Espeon even if they introduced 695 new Eevee forms...
New storyline(Not the old ten year old sets out to be champ and stop bad guys) : Eh, what would the new storyline be? Better to save that type of thing for the spinoff games.
Now, what else I want to see:
*Female Player character in a Japanese school uniform! Or a frilly floral dress! Or fully customizable characters.
*A cat-like Pokemon that's actually good in battle for a change.
*No more bringing back old characters! There's one in particular that I'm sick of seeing him over and over again, and even with the others, there's no logical storyline reason why they need to appear in newer games . Time to just drop them all completely and move on.
*I want to be able to place items in my PC box again, regardless of whether my bag is a "bottomless pit." I hate having to carry around stuff that I'm not even going to use during the main storyline.