One of few bright spots in the retailing scene Aeropostale ARO (NYSE), the teen retailer, announced today that its longtime CEO going back to 1996, Julian Geiger, would be stepping down at the end of the fiscal year (see press release). For now, the firm will replace Geiger with Mindy Meads, the president and chief merchandising officer, and Thomas Johnson, the chief operating officer, who will serve as co-CEOs. Both executives have performed terrifically at the firm. It is unlikely, however, the two will remain as co-CEOs for very long. Co-CEOs is usually difficult arrangement under normal circumstances but it is even more problematic in a retailing situation.Keep a close eye on how this all shakes out over time. The company does not want to damage a good thing.