So you're eagerly awaiting iOS 6 in the fall, but you'd like to know just how many features you'll end up skipping if you cling on to your existing iPad, iPhone or iPod touch for one more generation. Apple has gone to the trouble of alerting would-be upgraders just what features they'll get when they check for the update this fall, and we've compiled it in a chart for an at-a-glance view of what you'll need. The short answer: you'll want an iPhone 4S if you're craving every iOS 6 feature. Some feature gaps are defined by obvious differences like the absence of cellular hardware, but the performance limits of the iPhone 3GS or fourth-generation iPod touch turn their upgrades into a patchwork. There's also a pair of questions about iPod touch support and whether or not "iPhone 4 or later" explicitly rules out the media player; we'll update should we know more. Either way, it's evident that Apple is bending over backwards to support burgeoning markets, but also that anyone who bought in 2010 or earlier is feeling the pressure to pick up something new -- especially original iPad owners, who can't upgrade at all.

iPhone 3GS iPod touch iPhone 4 iPhone 4S iPad 2 iPad (2012) Chinese service integration X X X X X X Facebook integration X X X X X X FaceTime over 3G/4G - - - X - X Flyover and turn-by-turn GPS - - - X X X Guided Access X X X X X X Made for iPhone hearing aids - - - X - - New content stores X X X X X X Offline Reading List - ? X X X X Passbook X X X X - - Phone replies and reminders X - X X - - Safari tab syncing X X X X X X Shared Photo Streams X X X X X X Siri - - - X - X VIP list, flagged/VIP mailboxes X X X X X X

Update: Since we first posted this, Apple has updated its support to add Shared Photo Streams and the VIP list support going all the way back to the iPhone 3GS. Support is much more consistent now, even if it still leaves the 3GS lagging in some areas.