I just put orders in for a few new iPhone 4S upgrades for the wife and I but I'm not sure how to keep her data (app data mainly, the other essentials are synced with outlook).
She has an iPhone 3G, so can't upgrade to iOS 5 then backup where my 3GS phone can. Can an iTunes backup of her 4.2.1 (latest she can get) iOS be restored to a newer iOS 5 phone, or will it only work on an equivalent 4.2.1 iOS-running device? Or...is there another series of steps to make that possible?
If not, is there a completely different way to get her app data off the phone and onto her new one?
Aside: I realize I can test this as soon as the phones actually arrive...but we're sending the current ones off for resale as soon as possible after getting the long-awaited upgrades. For that, I'm trying to get anything I may need to order for the transfer, etc. taken care of ahead of time.