Well, no, not really. But check out their 2009 Guide to Passover in which they state:
To kasher a dishwasher, one should wait twenty four hours, make sure that the dishwasher is clean, and then run two cycles. If the dishwasher is plastic, there is a debate as to whether one may kasher it, and an Orthodox rabbi should be consulted.Not only do they state that there are opinions that plastic can be kashered, but there is no mention of any problem with the racks, which are often rubber-coated metal.
I couldn't find last year's OU guide, but here is a 2007 link to an OU-affiliated shul which references oupassover.org and which clearly states "Dishwashers may not be kashered for Pesach".
This is similar to the Star-K's opinion, which states "One may not kasher a dishwasher from treif to kosher, from chometz to Pesach, from meat to milk or from milk to meat. This is true even if the interior is stainless steel, since all the hoses, fittings, pumps, etc. cannot be kashered."
Chicago's CRC similarly holds - based on a Rema - that dishwashers cannot be kashered, classifying them with sieves and other utensils that cannot be made perfectly clean before kashering.
Sephardim are generally more lenient in their approach to this issue. For example, "Gateway to Halacha" states that one simply needs to "clean away any tangible Chametz and run through one cycle empty. Some recommend replacing the racks for Pesah."
The most lenient opinion from a respected posek is that of Rabbi Yitzchak Abadi who states: "Any dishwasher can be used for dairy and then immediately afterwards for meat & vice-versa. And the same goes for Passover and non-Passover uses one after the next."
(BTW, if you are unacquainted with kashrut.org, browse through some of answers R. Abadi has given to various questions on kashrut - you will be quite surprised! Unfortunately, halachic sources are not included in the vast majority of answers, although one interesting post left by Marc Shapiro provides some sources for an important shitah of R. Abadi: that one can rely on intentional bitul by a non-Jew and basically just read the ingredients of a product to determine its kosher status!)