Thanks for mentioning the MS Surface Studio. I had almost forgotten about it. That alone is a strong reason right there to release a redesigned iMac.
http://www.patentlyapple.com/patently-apple/2010/08/the-mother-lode-welcome-to-the-imac-touch.html
Back in 2010. Seems some TVs from CES have gone further, with the screen alone at the top, power/data cable to a bottom unit with speakers etc like an iMac G4.