Which Way The Market

I am hearing predictions by brokers, financial planners, talk show hosts and the talking heads on TV that the market is going back to its old highs - DOW 11,700 and NASDAQ 5000 here we come.

It seems to me that in 2000 I heard these same people saying there was no top to the market and were looking into their crystal balls for DOW 30,000 or some other fantastic number. Suddenly the market turned over with the DOW dropping 3,000 points and the NASDAQ losing 80% of its value. Can it happen again? I don