I noticed that this chart still shows quite a few Android users in versions 2.3.3 - 2.3.7 (API 10, was it?) but 2.3 - 2.3.2 are gone.
Just to see the progress, here is the final calendar quarter of 2013.
It makes me think that the LG Optimus One and Optimus 2 are still around in many variants since those had so little storage that they couldn't be updated. They were also not very powerful, but they were inexpensive and people who could only afford a feature phone could suddenly afford a smart phone.
Notice that Honeycomb, version 3.2 is still there. Apparently, there were quite a few US$100 tablets that couldn't be upgraded but are still in use.
Update 2013.11.27: I've read recently that they re-worked Kit Kat to be less demanding of resources, i.e. to get rid of the reason phones are still using Gingerbread/version 2.3.x. It isn't likely to put Kit Kat on LG Optimus One variants but possibly the Optimus 2, which is still being sold.
I also saw today where the deal for BlackBerry/RIM fell apart and there doesn't seem to be a saviour of the company. That drove a sell-off of the stock, sending the price down about 20% lower. They also replaced the CEO. (I suspect that they'll be saying that choosing him was an error in Heinsight. Yes, that's mine, and stop groaning.)
I would think that Apple, Google, and Microsoft are looking to buy the remains of the company when it's too far gone to save.
Google doesn't care about real-time execution since it chose a Java-related runtime architecture, but Apple could really use something a bit better and BlackBerry owns the QNX operating system, which was always quite a stunner with its fast (operating system) message passing system. Anything to fix the performance issues in the Darwin/(Mac) OS X kernel would be good. (Sure, it's easy to make the slop less apparent with faster processing but it's still sloppy.)
Apparently, the BlackBerry Messenger (BBM) has been downloaded quite a lot, but people don't know what to do with it once they have it. Duh. You should be able to contact someone on CNBC as they're saying that "You'll have to pry it from my cold, dead hands." That's CrackBerry, and most of the users have been gone since about 2009 when they realized there were alternatives.
It'll be sad to see them gone from the market. I wish they had taken Apple's entry into the mobile phone space seriously. Obviously, Nokia had a similar take on being unbeatable and it cost them plenty.