It isn't actually news--apparently, it's been going on for at least a couple of years. I'm a moderate news junkie--I wonder if my missing this when it came out should make me feel even more paranoid.
After having printed out the test sheets, I read the article more carefully, and found that it's just laser printers. Presumably, an ink jet is capable of maintaining discretion.
Of course, most printing doesn't carry any risks, but what if you did want to make sure your printing wasn't water-marked?
I'm not sure that using a black-and-white xerox machine is good protection--it could still have a yellow ink cartridge. The best bet would be either using a machine that you can check for extra cartridges. Failing that, there's something to be said for places like Staples which use the honor system for payment rather than Kinkos, which uses a tracable payment system.
Here's somewhat more:
Addendum: It's not just the principle of the thing, it's the money: one of the commenters to the schneier article realized that the forensic dots were why his yellow ink kept running out even though he was only printing in black.
The Other Addendum: I got the EFF link from Marginal Revolution, an economics etc. blog.