Research and Development
iSync has been removed presumably because it has been one of the “low usage” applications on the platform.
iTunes is the centre of most of the Mac based synchronisation these days, along with MobileMe for the cloud side of things. However, iSync has been a key feature of the OS for users still carrying non-iOS phones (i.e. Nokia E71), enabling them to seamlessly synchronise their contacts and calendars with phones.
All that was needed was to just copy over iSync back into the /Applications folder, and also copy the phone plugins to the /Library/PhonePlugins folder.