So shortly after Microsoft announced that Lumia Denim update had begun rolling out for most of its low/mid range devices in China, the update begun rolling out to other countries in Asia and Europe.
Updates have been reported in India, Egypt, Indonesia, Czech Republic and more.
You can check if it is available for your phone in your region by going to the Microsoft Update tracker
But this Denim update is only rolling out to most Lumia phones, just except the 1520 and 930.
These are the 2 most recent Lumia phones that have the necessary hardware to support the coolest features on Denim (Imaging and passive voice activation "Hey Cortana")
Yet the update to these couple of Lumias is no where to be found.
Looking at what Denim would do to the 1520 & 930, it is safe to say this update is going to be toally different from what is rolling out to current Lumias right now.
So maybe it is not even ready yet, hopefully it will be just in time for christmas?