"...fragmentation is going to kill Android unless Google does something about it."
I don't think so. I think most SP owners download a lot of free apps and few pay apps, keep the most useful and most fun ones and remove the other ones. I just saw some recent statistics which said that the average time people spent on smartphone gaming is already on a decline (and I bet it will decline even more), while the average time spent on social networking is increasing quickly. I think most Android users don't and won't care about the OS version of their device as long as they can play Angry Birds and one or two other games from time to time and as long as they can use Facebook, Twitter, LinkedIn like on any other phones. Fragmentation won't kill Android, Android won't kill iOS.
On a related note:
I just bought a Nokia Lumia 800 because Windows 7.5 is the phone OS I like the most (love the metro UI in combination with the phone design). When I bought it I was already pretty sure that the OS won't be updated to WP 8 (and a few days ago it's been confirmed), but I don't care. As far as I understood, WP 7.5 device owners will get a few of the new (and afaik still unannounced) features of WP 8. That's more than I expected but even if WP 7.5 wouldn't get any of the WP 8 features, I'd be completely satisified with my new phone as it is.
At the same time I bought my Lumia 800 (launch price 500 €, street price currently 320 to 350 €), my father ordered a Huawei Y200 for 99 €, an Android Gingerbread 2.3.6 phone and according to hardware reviewers currently one of the best smartphone offers for around 100 €. If I hadn't told my father about iOS/Apple, Android/Google and WP/Microsoft, he wouldn't even know the names of any phone OS. He definitely won't care about the Android version of his new phone.
My nephew got some Samsung Android phone and doesn't care about the OS version. Several colleagues and friends of mine got Android phones, some of them don't even know what Android exactly is let alone that it's owned by Google, most of them don't know that there are different Android versions on different phones, some do but don't know or care about the differences. (Yes, I asked them these questions, because before I made up my mind I was interested to know what people do with their phones, what they like and dislike about it and if they cared about software updates or the fact that other people got more "up-to-date" phones.).
This is all anecdotal, but my point is:
Tech sites should not overestimate the impact of OS versions. I'm sure that the majority of smartphone owners just don't care.
The more interesting questions regading SP apps are imo:
When will the app boom be over?
Will ever see a consolidation of the app market or will we forever just get those somewhat childish news about "700.000 apps now available on your phone", "...now 1 million available. Imagine the possibilities !!"?
Do phone reviewers even realize how ridicilous they sound when they claim: "Still one of the biggest disadvantages of Windows Phone: Only about 100.000 apps available at the moment as compared to 600.000 (iOS) and 750.000 (Android)"? Do these guys think I'll check all 100.000 apps on my phone and my nephew all 750.000 on his phone? Or do they mean with this comparison that the chance to find great/useful/fun apps is more than 7 times as high for my nephew than for me? And If so, how can he find them?
If I was an app developer I wouldn't be worried about Android fragmentation, I'd be worried about drowning in a sea of competitors and media which will forever list Angry Birds, Doodle Jump, Instagram, Shazam and 46 other usual suspect as "50 must-have apps".
