Here are some of the features I would like to see:
Better camera controls; I like the grab and drag that you see in the quad view, but add more flexibility and make it the normal and it would be awesome.
A built in help/feature guide; something that would tell you what something does if you don't understand it. Maybe a right-click What's this? system or something.
Synchonizing the right-click do-right-now method list and the drag-and-drop code-piece method list. I realize that some of the methods don't work like that, but it would be nice to see the ones that do in both.
Undo/Redo drop down list; sometimes after I have done a series of things that I want to undo, I don't know how many times I have to undo whatever I did until it's completely gone. It would also be good if more things were undoable.
Wider speed in play range; make it so you can play your program slower as well as faster.
More objects; although I figure you are doing that already.
A codeshare function; click on the button and select a section of code, method, object & object property list, or the entire thing to show off to fellow users or get input on why it isn't doing what you want. If you do this, you should make a page on this forum to share the codes on.
A see-what-you've-got clipboard; make it so you can click on the clipboard and see what you've got on it, and maybe be able to store multiple things at once.
A replace-all-with function; click on the button and be able to replace every instance of a selected object with a different object.
If I think of anything else I will post it on here.