Remember the runup to Y2K? The predictions of catastrophe? The hand-wringing over unpreparedness? It's happening all over again, on a smaller scale, with the runup to the cash launch of the euro. Although the new European currency will not be legal tender until New Year's Day, armored trucks will start rolling this Saturday with the first loads of bills and coins for banks and stores across the 12 participating Continental countries. Pessimists are already tallying the opportunities for logistic disaster -- from security failures to cash shortfalls -- while even the most optimistic economists fret about the potential for a short-term depression across the entire euro zone once the coins begin to mix on Jan.1.

Two years from E-Day, no doubt, the mammoth transition will look about as catastrophic as Y2K does in retrospect: that is, hardly at all. There are sure to be bumps in the road, but, as European Central Bank President Wim Duisenberg says (it's part of his job description to be soothing, but history bears him out), there are few indications that "could place the effectiveness of . . . preparations for a smooth and successful cash changeover in doubt." The "euroization" of Europe from the tip of Finland to the bottom of Greece (but excluding Britain, Sweden and Denmark, at least for a while) is a foregone conclusion. Europeans now being born will grow up knowing the franc and the deutsche mark, the drachma and the schilling only as exotic words in their storybooks.

There's the rub, of course. It's not the reality of the euro that's in doubt, but its desirability. Oh sure, everyone knows the economic arguments in favor of it: Euro-zone trade will get a shot in the arm as the last barrier to a single market comes down, and inflation should be easier to control with readier comparability of prices and wages across the region. Besides, the great European centralization enterprise is already so far along that separate currencies have not really been an option for years.