Surprising analysts, Wal-Mart is slashing prices of HDTV television sets well before the Christmas-season discount wars ordinarily begin. The company said on Friday that it has cut the price of its RCA 32-inch LCD set to just $847. The Polaroid 37-inch set, which had been priced at $1,297, was cut to $997. And the price of the Panasonic 42-inch set was cut $500 from $1,794 to $1,294.