It's not "that" powerful. It's still a 65w CPU. Mac mini must now be able to hold a full 10 core CPU, but these have a massive TDP which, I think, cannot fit the actual cooling system of the mini.
Apple might not care and still stick a '65w' Comet Lake S CPU in to the Mini if they can get a BGA variant.
But I think they have bought themselves some time with the Mini by 'refreshing' it in March. I think they can wait a year there and consider a
Rocket Lake CPU - especially if the Intel Xe GPU is coming along nicely by then. It might even silence some of the naysayers.
20 PCIe lanes - up from 16 in Comet Lake and before. I see extra Thunderbolt ports in the future here.
DMI x8 connection to the motherboard
Intel Xe graphics (with HDMI 2.0b and Displayport 1.4a support)
Thunderbolt 4 - (which is basically Thunderbolt 3 + all the USB3 standards including 3.2 at 20Gb/s)
I actually love the idea of an iMac Air. I can definitely see the 23" coexisting between the 21.5" and 27", but one thing I just can't see clearly is how Apple will define the different resolutions between the different iMacs, since we have clear cut 4K (21.5"), 5K (27") and 6K (32") displays. If the 23" is going 4K, we're going to see a drop in PPI.
It depends how Apple are defining 'cheaper' as per the leaks. A quality 23" product will ignore the LG UltraFine 4k panel and be 4.6K.
A replacement for 21.5" iMac would be 'classic' 4k a the lower resolution to bring in the people who think 21.5" is too small regardless of the 4k resolution.
The question about storage (HDD/Fusion/SSD?), and presence of T2 (or not) could be addressed at the same time.
- Apple's customer input may have told them 27" is an acceptable size for the larger model, whereas ~24" was more preferable than 21.5" for the smaller;
- The decision is being driven by the availability of screens - 4K @ 24" might be easily available, whereas the only options for 5K might remain the 27" (unless one goes ultra-widescreen, which Apple/customer input may not favor)
Another point comes to mind here, if Apple are getting rid of the 21.5" model wholesale, that they still have the non retina 1080p panel in the base 1080p model.
If they are getting rid of all three SKUs why couldn't they drop a 4k panel in the base one and put a 4.6K panel in the upper SKUs? This would answer both schools of thought by offering both panels because while 1080p might be acceptable in a 21.5" model they would be pushing it to find a quality 1080p IPS panel in a 23" size these days.
They may certainly not be in favour of doing something like using a 1440p panel in the base 23" because it could actually offer 'more' desktop screen real estate by default than a 4.6K model for example so the Ultrafine 4k panel could possible serve as a low SKU.
Marketing-wise the 23 iMac could come with '4.6K Retina panel' and a '4k panel' as display options.