I think the 27" iMac provides a market-leading monitor, no need to go bigger. I'd really like to see a new iMac that provides very robust cooling for the latest intel processors, while also providing upgradability for RAM and SSD. Bezels could be made slimmer, that would be nice, but far down on my list. I'm typing on my 27" iMac right now, and I don't really notice the bezels when I'm doing actual work. The potential ARM transition would be a very interesting transition to see happen, however, every chip series has a performance ceiling; I'd be curious to see a comparison of intel vs ARM in terms of which architecture has the most headroom over the long-term.