Like the title says...if a new OS comes out and i re-jailbreak is there any way to have them sync to my itunes so i dont have to re download each one?
Cydia will have a feature like you want soon.
http://gizmodo.com/5738079/cydias-new-feature-lets-you-save-your-jailbreak-apps
this is an awesome feature...every time i re-jb i have to search to all the repo's coz i wouldnt remember from which repo i downloaded a particular tweak.. now it makes the whole process a lot simpler..
Actualy this new cydia feature will not add any non stock repos you added or even display packages you installed other than ones purchased from the cydia store.
Its a good start but still wont save and install all your repos and downloaded packages from various vendors and repos.
now that is disappointing.. but as u say its a start, so lets hope in the future further tweaks are added to this feature..