Oh no, not another... oh wait, it's Official.

I'd like to see Aces concentrate on a new engine etc etc from the ground up that as far as visuals go can generate and depict good detail close up and grade it further out to keep performance okay, as well as improve flight dynamics in areas that need it. I'd be prepared to say goodbye to backwards compatibility IF THE RESULT WAS WORTH IT and the default aircraft were as great as some of the FSX ones are. AND - ACES developed a user-friendly programme set that allowed both freeware and payware developers to get to grips with the new system quickly - this is crucial!
Regarding looks and content:
I'd like to see better textures (Ground Environment style) with some real local feeling - like Indonesian autogen doesn't look the same as Chicago, a better visually and more user-configurable weather interface (REX or FEX or AS style), lots of local content like the great detailed sceneries for FSX (Rio is one of my favourites) and more aircraft like the default Beaver, Goose, Merlin, F18 which are really great to fly.
Perhaps Aces could extend cooperation with external sources to bring this mainly visual-enhancing content into the sim, out of the box, so they can concentrate on the bare bones of the sim. I wouldn't hope for the sim to look like Crysis, I'd be happy for it to look exactly like FSX if it would run smoothly. However, more detail, more content, still more immersion would be awesome.
Regarding other features, I'd be particularly interested in:
1. Better flight planning interface so it's possible to really plan something thoroughly using FS only using the map in there, do calculations needed, get distances and bearings from one place to another by clicking on the map (like SkyVector), see magnetic variation etc. Obviously within the limitations of the FS map, I wouldn't expect en-route charts for the whole world or anything.