My mining days are shrinking and I am going the buy and hold route more then ever.
And that is part of the reason why miners selling off all their BTC will not drag the price all the way to zero. If the price drops by enough, even existing holders of BTC will be happy to buy up all additional coins that come on the market. It certainly won't drop below $10 (at least not on account of miners alone), probably not below $100 and it wouldn't surprise me if even $200 proved a firm and unbreakable support. Once the price stabilises, the global hash rate will adapt to the rational level given that price.