My most-likely option would be buy the Apple Studio Display Pro (when it comes out at WWDC) and pair it with my M1 Pro MacBook Pro 14" in clamshell mode because my MBP is just as effective as my 27" iMac at making a living and I want to stay with a Retina-quality display.
I've said it before in this thread, I'm really feeling stuck between a rock and a hard place, as I too was holding out for an upgraded 27" iMac.
I was hoping to downgrade my current MBP to an MBA. I've always preferred the MBA, but just couldn't justify getting one back in late 2016 when my old one died and it still didn't come with Retina... My macbook is my secondary computer, it doesn't need all the power I need in my work horse. So for my mobile mac, I definitely prefer mobility over power (and I just absolutely prefer the form factor of the MBA over the MBP, even after 5.5 years of having been a MBP user, even more so with the new MBPs).
The mini is not an option by a loooooong shot.
I'm now considering the 24" for its all-in-one package, but continue thinking it also isn't really an option I'm eventually going to choose. I really don't want to go down in screen size for my desktop main computer (and it also maxes out at 16GB RAM).
There's also no way I'm going away from Apple-quality displays (aka 'choose a display from another vendor').
The studio is cost prohibitive for me. That's just the realitiy of it.
So the only option left is to get a high-spec as possible/affordable MBP and pair it with the Studio Display. Which stings, because I really really didn't want to get a MBP again.
And I also actually really like to have two macs, one dedicated desktop and one mobile; I often have some code running on the desktop while I'm out and about at work with my macbook. That solution would greatly reduce my multi-tasking capability. It would also completely take away the option for my husband to work on the mac at home while I'm traveling (which I do quite a bit and for which I need to take my macbook with me).
So for now, I'm just trying to keep my current macs from dying (they're both on their final legs) as long as possible and hope that Apple will come up with a larger screen-sized iMac that fits inbetween the current 24" and the studio (both in price and in specs) before I definitely need to upgrade. I guess, if that doesn't happen in time, I will end up going with the 24" as this seems to be the cheapest interim option.