It looks like the Lumia Denim software upload is now starting to hit a few of Microsoft's smartphones in Europe. The Lumia-maker has published a support page for the Denim update where owners of Lumia devices in Europe can check their country and phone model to see if the update is available. For now, it looks like variants of the Lumia 625, Lumia 520, Lumia 530 and Lumia 1320 are starting to see Denim in select countries.
Microsoft asks that you be patient if you haven't yet seen the update for your device:
Your phone notifies you once an update is available. We ask you to be patient as updates for Nokia Lumia range are always released gradually.
All in all we count 69 Lumias getting the update, which is not too bad.
Thanks to Dimitar K. and Silviu B., for the tips!