I don't mind the iMac all-in-one styling for some purposes. My biggest gripe is repairability / upgradability.

When it takes 1-2 hours to swap out a hard drive, some engineer needs to be whipped with a Cat5 of 9 Tails:

I'd love to see someone come up with a standard that would allow you to mount a mini-style computer to the back of the monitor WITHOUT having a rat's nest of cables going all over the place. There's no reason they couldn't come up with a connector on the back of the monitor which could provide power, video signal, USB, etc. that the mini-PC could attach to. You could still even use the VESA-mount holes for backwards compatibility with older monitors.