In conjunction with the announcement of the iPhone 5 and new iPod models, Apple has released iTunes 10.7 to add support for iPhone, iPad, and iPod touch models running iOS 6 (scheduled for release on 19 September 2012). Additionally, it adds support for the latest iPod nano and iPod shuffle models. With no new features, iTunes 10.7 is just a compatibility stopgap until the next major release of iTunes appears in October. (Free, 157.33 MB via direct download or 163.3 MB via Software Update)
Extract Directly from Time Machine
Normally you use Time Machine to restore lost data in a file like this: within the Time Machine interface, you go back to the time the file was not yet messed up, and you restore it to replace the file you have now.
You can also elect to keep both, but the restored file takes the name and place of the current one. So, if you have made changes since the backup took place that you would like to keep, they are lost, or you have to mess around a bit to merge changes, rename files, and trash the unwanted one.
As an alternative, you can browse the Time Machine backup volume directly in the Finder like any normal disk, navigate through the chronological backup hierarchy, and find the file which contains the lost content.
Once you've found it, you can open it and the current version of the file side-by-side, and copy information from Time Machine's version of the file into the current one, without losing any content you put in it since the backup was made.