This is just my 2-cents but:
Run-time Object, Layer, Event Sheet Loading: I'm not sure if any of you have heard of a fighting game engine called MUGEN (Most people tend to think it's just a game). MUGEN is rather famous on youtube because was centered on custom content, from characters and levels, to even GUI modifications. Almost everything the game was, was user created. Anyway my idea is the ability to not only export entire games through construct, to export individual frames, event sheets, and objects which could be loaded at runtime through an event kinda like this.
(At Character Select Screen)
Check {Directory}
For every .char file
Add File Name to Ingame List
(At Fight)
Start of Frame
Load Object from {Directory}/{player1char.char}
Load Object from {Directory}/{player2char.char}
And something similar could be done with frames, although those would have to be loaded at the end of the last frame.
And on a secondary note, this would also be nice for the editor. Loading individual frames, objects, and even sheets.
Event Sheets included with Objects: This might just be my past experiences with MMF2, but I do think this might be a decent idea. MMF2 allowed a feature that let you have event sheets in objects. The feature however was borderline broken last I checked, most of it's usefulness was eliminated by the fact you couldn't include qualifiers (families). If something similar to this were included and did allow families, it would make coding for very object based games alot easier.
I guess this would kinda go with the previous one though.
3D:I know I'm gonna get flack for this; but basic 3D camera movement, collision, animation, and maybe even hopefully lighting would be quite nice if possible by 2.0. And it's not like any progress hasn't already been made toward it, construct can already use 3D models (And boxes for awhile), collision and camera are (Somewhat) fake-able at this point, and I do believe I've seen 3D lighting at work somewhere on the site (Or something close, correct me if I'm wrong) and construct isn't even at 1.0 yet.
Of course Construct has gotten this far, who knows where it'll be when Construct 2 is out.