It is simple supply and demand. We have more demand at a lower price. That doesnt mean that price is starting to appreciate, only that we will have to crash through multiple demand levels on our way down. I think most people care about price bottoms, not sales levels (though the two are connected). So we hit a sales bottom, doesnt mean we will start seeing appreciation, which is the natural conclusion if you are telling everyone to go out and buy now. We all saw the demand levels back in September 07, and things economically have only gotten worse since then. There is no support for price appreciation right now, not when the only thing driving the increased sales is falling prices.
Take an example in the stock market. RE moves alot slower than stocks, but we can have plenty of days when stocks are crashing and the sales numbers are way way up. Does that mean it is a good time to buy? Maybe, maybe not. You need more info than that.