Of course it won't. That just reads like hyperbole. Apps on iOS7 will work almost entirely the same as they do on iOS6 and below.
I'm not up in the city right now, but from the few podcasts I've listened to - people are already commenting on how "dated" their app feels.
And - with the exception of the Mail/Calendar (Apple Favoritism, at its worst) and wacky "geofencing wakeup in the background techniques", all of our backgrounded Apps on iOS have basically gone to sleep permanently (until user pulled them back into the foreground) unless they were a GPS/VOIP/Music/Newstand app (and even some newsstand apps performed poorly with background downloads - I'm looking at you NYT).
In addition to the 3-D geometry (where I'm expecting lots of slide over sheets as a new metaphor) - I think all developers are right now considering how they can take advantage of an App that they can "wake up" remotely from a notification and perform activity with.
And people are in shock after years of iOS looking pretty much the same. When everyone actually looks at things objectively, they'll realise that their apps need to look a little different, behave a little different, but overall be pretty much the same apps they were before.
What annoys many users (and every developer is also a user) is change for the sake of change. There is absolutely no technical reason for changing the style of icons on iOS 7. Clear fit right in on the iOS 6 home screen and was a joy to use regardless.
Sure the new APIs might offer some great features for apps and I am sure they will definitely be used in the majority of upcoming apps, but my problem (maybe not problem just curious observation or minor annoyance) is Marco taking a completely nonobjective stance on the iOS7 changes. I am completely ok with his opinion but the blind hyperbole is a bit annoying.
And don't be so quick to say, "or even what Android and Windows phone offers.." - Those are awesome platforms, and Apple can learn a lot from them (as Android and Windows have learned from the iPhone.) Indeed, the "Cards" approach in multi-tasking is actually reminiscent of what Palm's WebOS did [2] - so Apple has learned from them as well.
I am very intrigued as to how well the Multitasking/Notification driven background/User-interaction-Dependent-CPU-scheduling-for-background-processess will work - That's pretty innovative solution to a common problem of Craptastic background apps that you don't think about sucking your battery dry. [edit: And all the discussions about Apps checking in when you've got the radios on, when you are powered up, etc... - I've been dreaming about exactly that for 2+ years. Finally! (Non-ironically)]
Don't kid yourself - iOS 7 is the big one, and, will likely be as ugly as the upgrade was from 10.6.8 to 10.7.0 was on OS X - My prediction is that iOS 8 will basically be fixing all the glitches and problems created from this complete platform rethink - but, sometimes, to make an omelet...
Forest Fire Indeed!
[1] http://daringfireball.net/2013/06/ios_7_signature [2] http://www.youtube.com/watch?v=c20uhGxSxWo