I been looking at FPGA mining because of the cost of electricity and Dec 2012. Well I figure why not just keep going the GPU route? Why not power your mining rigs with wind/solar power? Sure there is a nice little start up cost; however, going green for your home means you qualify for tax credit. So for us with a set goal in mind for our desired hashing power wind/solar makes sense. Instead of investing in FPGA the offset cost between GPU and FPGA can be spent on going green. So you get same energy cost if you were running FPGA and you get the cheap hashing power of GPU.

So assuming 36 6870 for 10Gh/s
11,500 cost of PC hardware (not solar/wind hardware)
5 dollars a coins

By Dec 2012 You could very well be in profit assuming you sale coins above 5 dollars. Also after you're ready to stop mining or bitcoin goes under you still have green energy to keep your bill down, PCs, GPUs that can be sold, no trying to find a use for your FPGAs, and the warm feeling of going green.