@arstechnica@gsuberland's comment was about SPD EEPROMs on memory modules, not in printer cartridges as the article suggests -- it's a comparably small amount of memory. The point is that they have the background to comment on the plausibility of such an attack.
@arstechnica one would think HP would be more concerned about people using (horrors!) third-party usb flash drives in HP-branded printers and computers. A nefarious supervillain can fit a lot more malware on one of those than on a printer cartridge lockout chip.