You won't find much help from Zune in keeping the look of your current WP7 to another one, if that's what you mean CJ Thunder.
The back up Zune makes is only your apps, photos, music etc.
You will have to reposition all your apps yourself once you have them on the phone again.
No snapshot copy (position of your apps) of your current phone if that's what you meant.
I actually wrote down the position of my apps on the home screen as i keep trying this ROM and that ROM and then it was easy for me to get back to normal as i am used to my apps bing in the same place LOL
Sad i know, but true. :)