As far as the denim update is concerned it started rolling out last year and has been updated to several Lumia models. Currently, it has reached Lumia 930 flagship. Rumors are that some 930 models might get it sooner than others. That is why; it reached late to EE in UK. It has been received by other regions for two weeks but EE got this late comparatively. Lumia Denim deploy algorithms add exclusive goodies like 4k video recording, features Rich Capture and improvements to image processing algorithms.

and improvements to image processing algorithms. Also the good news is Nokia Lumia 930 will be the one eventually getting Windows 10. If you have bought or about to buy Nokia Lumia 930 from EE you can check for updates available there.

Nokia Lumia 930 will finally get Denim Update and Windows 10