Will it require liquid hydrogen to cool the superconducting magnets, or will it use new high Tc superconductors and liquid nitrogen?  It will use superconducting magnets, right?  Otherwise how is it going to suspect the spinning torus?  Also, what will the fusion reactor run on?  I'm assuming it won't just run on garbage like the one in Back to the Future - that's clearly not possible in real life - so will it need a special fuel?  We need answers to these questions now, otherwise how are we to make estimates of mining profitability?