Morgan Stanley just announced massive layoffs at its residential mortgage business; it's shutting down the UK end altogether. One suspects that more than a few senior managers are thinking wistfully of the Glass-Steagall days. The Dean Witter merger was . . . well, the less said about that, the better; now their attempt to diversify into the Savings and Loan business has met a similar fate. Stand by for corporate retreats in which highly paid management consultants are brought in to lecture the executives about core competencies.