[bradleyland]

I'm not sure why you'd say that. There's a lot of misinterpretation going on here. Read the text carefully (emphasis mine):

> new iOS apps uploaded to the App Store must include 64-bit support and be built with the iOS 8 SDK

You must include support for these items. There is no suggestion or requirement that a developer not support iOS7 (or iOS 6 for that matter).

This also only affects new apps. So basically:

* This only applies to new apps [1].

* This only requires that new apps include support for iOS 8 [2] and 64-bit.

* Developers can still support older versions of iOS.

That's just the basic breakdown of Apple's expectations. Your customers might still demand support for older iOS versions, so this isn't much of a change as far as legacy support goes.

1: I suppose it is open to interpretation whether "new iOS apps uploaded to the App Store" includes updated versions of older apps. It doesn't sound like that to me though.

2: Just because you use the iOS 8 SDK doesn't mean you can't/don't support earlier iOS versions. Quite the opposite actually, as iOS SDKs have specific provisions for supporting older versions (note, I'm not an iOS dev, but this is what I hear).

[0x0]

Building with a new SDK makes the app opt in to new behaviors even when targeting older iOS versions. This can be quite a hassle. Your perfectly working app - even when deployed on an iOS 8 device - will suddenly break in many fun ways merely from recompiling with a newer SDK: touch handling differs, margins may be weird, table headers vanish because various new methods aren't implemented, screen rotation suddenly gets enabled where you didn't expect, new keyboard metrics mess up your layout, etcetc. This happens because when the runtime detects that an app is built with an older SDK, it enables a bunch of compability behaviors that newly built apps cannot opt in to.