When Google announced Android 5.0 Lollipop, then called Android L, earlier this year, the question that was on everyone's lips was when devices would be able to get the update, which features a complete design overhaul for Android, including a new notification center, lock screen, and battery improvements. Whilst Google's own Nexus line is set to get the update in early November, devices from other manufacturers, such as Samsung and HTC, are set to get the update a little later, though we didn't know how long it would take until now.
Sources have confirmed that the Android 5.0 update for the Samsung Galaxy S5 is due to land in either late November or early December. However, a specific time period wasn't given, which means that we don't know exactly when the device will receive the update, or how long it will take for specific versions of the phone on different carriers will receive. All this means is that there might be a month or so from the initial rollout of the update before the device gets the update in all regions.
For devices made by other manufacturers, it will depend on the manufacturer themselves in how quickly devices are update with the new version of Android. As stated before, Google's Nexus devices, such as the Nexus 5 and the Nexus 7 (2013), will receive it first. HTC has previously stated that it plans to bring the update quickly for its customers, stating that the company will begin to rollout the update for their selected devices within 90 days of receiving the final software from Google. I'd assume that devices released in the last year or so are bound to get the update. Sony has openly stated that it will bring Android 5.0 Lollipop to the entire Xperia Z series, and Motorola has said the same of its devices, though both these companies haven't released a release schedule for these updates.
All this means is that most of the devices from these companies released in the last year or so are going to get updated pretty quickly by the manufacturers, which means that everyone gets to play with Android 5.0 Lollipop.