I'd love to run ECC RAM, but I'd have to buy a much more expensive processor, a much more expensive mainboard, and all of my RAM would have to be swapped for moderately more expensive replacements. And DDR3+ is not cheap.
I'm curious though, if ECC consists of a ninth parity bit, is there any reason why a memory controller can't be designed that would, worst case, use every other (identical) stick just to get parity bit(s), as a BIOS configurable option? Sure it'd halve your RAM, or you'd pay a lot more in RAM costs, but not having to buy Xeon processors and mainboards, and getting to reuse your existing RAM, would be worth buying an extra stick of RAM in my opinion.
It seems as processes keep getting smaller, and RAM sizes keep getting larger, that the effects of cosmic radiation are just going to keep getting worse. If we can't get desktop CPUs and mainboards to just switch to ECC, surely this would at least be a better-than-nothing option.