I think of my machines running bitcoin as slot machines. I put in CPU time and energy costs in at a regular rate, and once in a while I get money back. If I'm to treat bitcoin as part of a business, then I need to be able to calculate my expected return on investment, just as a casino owner needs to be able to calculate how much money she's making off of her slot machines. I know that the bitcoin generation difficulty will stabilize at some point in the future, but at this point it would be useful to me to be able to calculate my ROI quickly and easily.

So, if nobody else is going to do it, I'll probably make a patch for this. Bitcoin donations appreciated, of course, and would help motivate me to make it available quickly.