Another important question: what is the expected lifespan of such an FPGA board running at 100% 24 hours a day 7 days a week? 6.8 watts sounds awesome but without knowing an average lifespan to amortize the hefty initial cost over I can't say with any certainty whether this is better than GPU mining, and if so by how large a factor.
I have no reason to believe it won't last as long as any Graphics card, if not better. The current cooling solution keeps the chip under 50deg, GPUs constantly run higher then that. The board itself is populated with quality components, most capacitors are ceramic and the remaining are polymer capacitors (that don't leak electrolyte).
The question remains of course, what if the fan fails? I'm sourcing for good ball bearing reliable fans. That probably is the thing that'd kill the FPGA, the rest of the board should still work though, those LMZ modules are very hardy and can take a direct short to the output. If you send the board back I can fix it at the cost of a new FPGA.
