I would prefer a check / uncheck selection of the items to be backed up like full browser configuration, bookmarks, wallpapers, passwords, cached files, cookies, plug-ins, add-ons and its configuration files and so on. Then store all together in a single archive file (like *.zip) and save it to local disc. Furthermore it would make sense to have an import function for those backup files where you can check / uncheck what to be restored.

I think this shouldn't be too hard and time-consuming to program and would be a great benefit for lazy people like me who wanna perform offline back-ups on a regular basis without tinkering in Windows user profiles or batch scripting.