For every Android update, Google's release of code to OEMs starts an industry-wide race to get the new enhancements out to customers. So how did everyone do this year? Who was the first with KitKat, and who was the last? What effect does your carrier have on updates? How has the speed of Android updates changed compared to earlier years?
Nice overview that may help during your next purchasing decision, and which neatly illustrates Android's biggest weakness. Interestingly enough, it doesn't include non-stock ROMs.