Samsung has begun rolling out Android 5.0.1 Lollipop to Samsung Galaxy S4 users in Canada. The update is released over-the-air, so you should receive a notification as soon as the new firmware is ready for you. Also, if the notification failed to appear, perform a manual check under Settings > About device > Software updates > Check for software updates. You can also try checking for the update via KIES. Grab the USB data cable, connect your phone to the PC, and launch KIES.
The new build number is I337MVLUGOC4 and is available for Bell, TELUS, Virgin Mobile, Koodo and SaskTel customers.
Android 5.0.1 brings with it several new features, major user interface enhancements, performance and stability improvements and much more.