Enthusiast iMac Pro?
Apple needs to build an upgradable iMac complete with desktop chipsets and no laptop parts. The upgrades would be handled in your Apple store of choice. This would alleviate the headache of your iMac becoming obsolete in a few, short years time and also cater toward the graphics design and gamer crowd since extending the life in most cases involves only needing to upgrade the memory and GPU.
iMac