Yes, it's true. I logged on to my account this morning and both sites are moving to Commission Junction. I've never had much luck with that program, simply because I don't seem to sell anything, but I am hoping that with luck and all the hundreds of posts with those two affiliates, and the 1600+ links I will be adding shortly, that I'll be able to sell something before they kick me out for inactivity. Fortunately, I can apply for other programs, too, and I hope that something will sell eventually!
So for now I will be redoing literally hundreds of links and hoping that I don't mess something up. As if I didn't have enough to do already!
Art.com has told me their former links don't work; however, I believe if you leave it all in place and use the Commission Junction auto deeplinker, that might work (if their pictures are still served from the same address after the change). If not, you can find the picture address, and use the CJ bookmarklet to generate a deeplink.
Art.com and allposters.com are also on VigLink, so it's possible if you have VigLink installed that will work, too. We'll see after the changeover!