Do Android phones get OS upgrades? I've been noodling on the next phone upgrade (notionally this Fall with the iPhone 5S). My impression is that an Android phone should be assumed to never get new OS upgrades or features after purchase; whereas an iPhone has been guaranteed a couple of nice updates over a couple years.
Is my 'conventional wisdom' out of date?
They get updates, it's just not as even as everyone else. I'll give an example.. when say, Apple comes out with new IOS or MS comes out with an update to Windows Phone, or even Blackberry to their OS, it gets pushed uniform. You're pretty much going to have it in a few weeks and everyone is about the same as long as same level device. (ie, don't expect Gen1 iPhone running 6.x.x etc.)
With Android, though, updates are out there, but carriers and devices may not update on the same timeframe. Therefore, you may.. or may not.. receive updates easily. This is a bit of an issue with fragmentation. Some devices are better about this than others, but it isn't as uniform as their competitors.
But yes, there are upgrades and they do happen in the field.