Can the content of an iPhone backup be extracted?
There are several apps for extracting backups.
The one I have used is Iphone/Ipod Touch Backup Extractor, it's been around for a while now and it is freeware, just make a donation if you find it useful to help the developer keep it updated.

You simply select from which backup you want to restore by pressing the button "Read Backups", then select from the list of application settings that can be restored.
There is a detailed step by step guide here