Well, there'll be plenty of time until we get news of a new One Piece movie - I'd guess end of next year at best - but until then we could share what we really would like to see in it.
First off, there's a basic poll question, consisting of the three main possibilities:
A normal movie like Movie 1-5 & 7, which consists of the Strawhats fighting a completely new gang of enemies with some side characters that are also made up particularly for that movie.
Then there would be the possibility of a more artsy movie, like Movie 6 was. It still has the same stuff as mentioned above, but it would feel very different in art, story progression and other stuff. People who watched the 6th movie should probably know what I'm talking about. Though I'd say it's very unlikely that we get a movie like that again.
The choice of a remake speaks for itself. I don't see how anyone would want that and it probably also won't happen again as they produce them for TV now, but it still was one of the things we've got before, so why leave it out?
A movie that uses some more canon stuff like Strong World and Film Z did, would probably still have a completely new antagonist, but would use more characters beside just the Strawhat Pirates from the original story. In itself these stories remain non-canon though.
I myself would really prefer the last possibility. It was great to see all the Marines in Film Z and also made Strong World - though to a lesser extent - more interesting, because it had some more connection besides "Oh, Strawhat Pirates!!".
I only hope it'd contradict less with the Canon then, because the Navy Headquarters from Z i.e. feels really weird now…
An idea that I had before, was that - if Oda doesn't plan to use all the places he just introduced in the Corrida Colosseum - they visit one of those in the next or one of the next movies. I think it could really be some great stuff to see the Strawhats visiting the Prodense Kingdom or the New World Central Fight Club.
So, what'd you like to see in the next movie?