Hi,
Recently it was pointed to me that the color of the selection outline makes it difficult to work with widgets. Since most widgets have a black border and the selection outline is also black most of the time the result is a 3px wide black border.
I think it would be a good idea to change the color and perhaps the style to something else. Here's my first attempt of a Visio-like style selection:

I'd like to hear your opinions on this. Any other suggestion is welcome!
You can install the development version to play around with this new selection to see how it feels:
http://wireframesketcher.com/staging