This post by an Android developer on TechCrunch very adroitly describes the mess that Google has made of Android:
Android’s fragmentation has become a giant millstone for Android app development, leaving it worryingly behind its iOS equivalent. It’s not the panoply of screen sizes and formats; the Android layout engine is actually quite good at minimizing that annoyance. It’s not the frequent instances of completely different visual behavior on two phones running exactly the same version of Android; again, annoying, but relatively minor. Device fragmentation is just an irritation.
OS fragmentation, though, is an utter disaster. Ice Cream Sandwich is by all accounts very nice; but what good does that do app developers, when according to Google’s own stats, 30% of all Android devices are still running an OS that is 20 months old? I sure would have liked to stop caring about Android 2.2 bugs fixed in 2.3.
And it’s not like those devices are going to magically stop working anytime soon. They could be out on the network for three or four years, maybe more, without security updates and with core components that can’t run current apps.
Android’s phenomenal market-share grab has come at a price. This is a real problem, and as I wrote a few weeks ago, it is inherent in the Android business model.
Ed Bott (@ wordpress.com) 
But it took IE6 the better part of a decade to get knocked out of top position…
This means that developers will be coding to Android 2.2 for quite a while to come. They’ll bitch and moan, but they’ll do it.
Until, one day, they don’t. As happened to IE. I mean, it’s getting to the point now where I see more websites with compatibility problems under IE than with other browsers (and it’s no longer because they’re hardcoded for IE quirks mode — but because they’re coded primarily for other browsers).
@Tom, of course I.E. 6 was so popular. Not because of what it was, but when it was. A decade ago was when the PC became vogue. And just like XP, it resided in untold numbers of computers that would barely be replaced anytime soon.
I’m just sick at how many people I have to talk away from Macs and Firefox back into truely modern software that really does do something for them other than put them at risk.