Seen on Slashdot.org, this brief article in InformationWeek discusses a new Flat-panel CRT technology in the works:
IBM scientists in Scotland have patented a way to make a color CRT that's 2 centimeters thick-and IBM says it's cheaper and easier to make these flat-panel CRTs than LCDs.
Short on details and time-frame... this sort of technology could certainly bring Flat-Panel iMacs into an affordable range.