As an owner of a iPhone 3G I don't agree with the solid green color that it gets. It was rendered unusable by iOS4.0, and although it was on "the current version" up until the release of iOS5 I don't recall it getting any actual feature from iOS4 other than faster javascript in the browser. So things are not as binary as depicted there.

It also seems like you're looking at Android through an Apple lens where the only phone updates come via the OS and having the latest version is the key metric. This means that e.g. any delay in releasing an iOS update has no impact on your graph, but if the Nexus team bust their chops to get an update out early, it makes every other phone look bad in relation.

What would it look like if you charted when the phones last received an update to their Maps, Youtube, or Gmail client apps from Google?. For Maps they would all be green I believe, less so for Youtube which is currently 2.2+ only so 15% of current devices wouldn't be able to get the latest version.

Glancing through the list of new features in iOS5 it seems to be equally split between a) things Android already had (twitter, notifications, no pc required updates), and b) things that are considered Applications, not part of the OS in Android (e.g. To-do apps, email/calendar improvements, e-magazine reader app) so there doesn't seem to be as much reason for Android users to have to upgrade.

So generally, from this point of view, you seem to be a bit loose with equating "support" from Google to mean new OS version e.g. your phrase "tracked down every update that was released for each device" isn't strictly true if you consider a newer version of Maps or the Market an update. And I would imagine the average person in the street would.