There is an update to version 7.7.1 of iTunes. To see the update, you can select Help in the iTunes menu bar and then Check for Updates. You will get a pop-up allowing you to download the 70.15 MB update which also includes QuickTime. According to the change log, the update, “includes fixes to improve stability and performance.” Hopefully we will see some faster sync time!
Updating iTunes will not affect your jailbreak or unlock.