It would be nice to be able to hold down the control key when resizing an image or any other rectangular component and have it preserve the Height 2 Width ratio.

Alternatly a checkbox next to the Height and Width fields for a component that would allow you to preserve the ratio when resizing would be fine.

I think in case of web publishing it would be good that the designer can set already if the App should fit to the browser's window, or what should be the background image or its color of the outher area of the app's dimension if it is not autofit to the browser.

I think it would be good to be able to specify the resolution when importing from common image/PDF/PPT files.

I got a bit of a problem to import my psd with several layers in it and with hi-res, that I had to save the PSD into a new file with a specific size and dimension than import the PSD.