Perhaps it's the economic slowdown; perhaps it's only people waiting for the holiday clearances to begin, but sales of high-definition TV sets have slowed in recent weeks. In an interview with today's (Tuesday) Wall Street Journal , Sanford C. Bernstein & Co. analyst Craig Moffett remarked, "It's not a coincidence that signs of a real turn in HD sales date to the middle of September, when the story of the stalling economy jumped from the business page to the front page with the collapse of Lehman Brothers. ... Consumers are justifiably scared and the wide-screen TV is among the most discretionary of purchases." If it continues, the slowdown in HDTV sales could also affect the satellite TV business, which has been competing with cable by boasting that it offers more HDTV channels than cable -- and selling HDTV packages at a premium rate, Moffett noted.