Right now at poloniex there are 40 million bts in the sell column. @1259 that's a little over 500 btc. In the buy column? 178 btc. Fodder for bears.
While this does mean something, you must also understand that it is heavily manipulated by whales to get the price to move where they want.
Whenever a whale wants the price to rise into his sell he adds a 100 btc buy wall lower down to make the buy support look good, and when he wants to buy more he adds a 5M bts sell wall higher up and pulls away most of the buy orders to make this look terrible.
Usually when the disparity hits extremes, its at a top or bottom and then it reverses and goes the other way.
As soon as a whale gets an order filled that he wanted filled, he reverses his walls so that it looks the opposite of the way it did before. If you buy and sell only based on the buy support and amount available for sale, you are just asking to get manipulated by these whales.
Of course, I am not saying that the buy support amount is meaningless, it does mean something.