My personal suggestion, though it is not listed on the poll, is that one of the S/PDIF inputs be used as an S/PDIF output. This would allow the Geek Pulse to be used as a USB to S/PDIF converter.
From all reports of the Resonessence Concero (which, in its "HP" guise is the most similar product available), it can serve as a USB to S/PDIF converter of similar quality to the under $500 dedicated converters.
Given lead designer Larry Ho's background, there would be few people in the world more qualified to work on the USB interface, so I would think the Geek Pulse could be made to perform this function better than most, even at the low price.
That would mean the Geek Pulse would have feature parity with the Concero HP (using the same DAC chipset etc.), with a much more powerful headphone amplification, and at a lower price.
Not to mention, potentially extending the useful life of the product and making it somewhat of a digital "Swiss Army Knife".
PS. I also hope that the rechargeable SLA-battery pack is offered as an (extra cost) addition, even if they do not get to $500,000. Getting a good supply of clean power is more than half the battle in making good sound. Most people would be surprised by how "dirty" their AC power truly is - especially around their computer equipment !