It’s been a while because I’ve been extremely busy last couple of months moving and at work but … there it is!
Fernando, this is the script you requested in the wishlist section, I hope it does what you need. As always any improvement or any bug, please people let me know and I’ll fix it. Thanks for your suggestions.

The script turns on/off the silhouette appareance of the objects, making their wireframe color black (customizable) and the viewport shade to object mode. It can be assigned to a shorcut key to easy access. The option menu is displayed when the user presses the shift key at the same time that runs the script, so the silhouette color can be customized as well as to affect only the selected objects instead of the whole scene (default behaviour). When the silhouette mode is off the objects recover their original wireframe color.

Download: [ Silhouette.zip ]