I see power costs talked about, but has anyone done the math?  Most of these ASICs take so little power that the power portion is almost nothing.  Free power doesn't really matter when you're talking about pennies on every gigahash.

I, for one, do not think the difficulty will stop adjusting at this rate for a long time.  I also do not think the price of a BTC will trend upward.  I think the days of making any more than a small amount on any less than a very large investment, are coming to an end, if not over already.