Why is it that everyone assumes the $:BTC ratio will always be $7.00? If the price on MTGOX goes to $70.00, mining would be as profitable as ever.
If you believe that the $:BTC ratio is going up, then it is more profitable to purchase BTC than it is to purchase hardware with which to mine.
Edit: If you already have hardware, then you have to look at two things:
1. If your electricity cost is less than your current income, it is more profitable to spend your money on electricity than it is mining.
2. If you have extra hardware that is not being used for anything else except mining (not being used for gaming, primary video card, etc), then it may be more profitable to sell the hardware for BTC. Or for $ to purchase BTC.