iOS 7 looks lovely, but it's not all about appearances; the new operating system is bringing some nice new features as well. But even if you get the upgrade, you might not get all the fun stuff that comes with it.
We laid down some of iOS 7's limitations on various devices right after WWDC, but this nice visual aid from The Apple Lounge shows it way better than words ever could. Looks like everyone who doesn't have an iPhone 5 or iPod Touch (or, obviously, the 5S or 5C) is out of luck in one way or another. Fortunately the super useful ones like multitasking and Control Center are coming to everyone, but things like AirDrop are a bit harder to come by.