My Nokia Lumia 930 got Developer Preview enabled. Lumia Denim is available for my phone but my phone can't find the update. (I live in Sweden)
How do I update my DP phone to Lumia Denim?
So, after some research, the short answer is: you will get the Denim update when it's available for your device. Being on the Developer Preview programme does not delay or prevent the update.
But if you're running a Dev Preview version of the OS, you may have Denim already but not know it!
Causes of confusion
The previous update, Cyan, was delayed for Dev Preview users because a bug was found when BitLocker was in use. This was eventually fixed and the firmware update was allowed for Dev Preview users.
There have been various reports of people getting the update only after unchecking the option in the Preview for Developers app, which is unusual as opting out of the Dev Preview programme doesn't downgrade the OS of the device.
What actually happens
Regardless of whether you're on the Dev Preview version or not, updates (OS and firmware) will install normally via Settings > Phone Update.
To confirm, look in Settings > Extra+Info...
If you're NOT enrolled in the Dev Preview programme, the version will be correct
But if you are enrolled, the version will be incorrect. Cyan will be listed instead of Denim.
If you go into Preview for Developers app, uncheck the option to remove your device from the Dev Preview programme, then check Settings > Extras+Info again - the correct version should be reported.
This is a bug with the Extras+Info app, not with the update process itself.
How to confirm this yourself
I used to following method to confirm the above...
Lumia/Nokia Camera issue
If you update to Denim while on Dev Preview, Nokia Camera is not updated to Lumia Camera. It is also not possible to find or download the app from the Windows Phone Store. The only fix so far is to reset your phone.
You just have to uncheck it in the Preview for Developers app. No need to restart your phone or anything.
The Lumia Denim update is being pushed out via the default update servers. The Dev Preview servers doesn't have the Lumia Denim update on them and therefor you have to tell your phone to use the default servers instead.