After creating the thread I read what a lot of other bitcoiners have been recently mulling over.  Here is a brief summary: proto-quantum computers exist (D-Wave based in Canada) and have sold for $10-$15 M to Lockheed Martin and Google/NASA Ames.  It is generally thought that these adiabatic devices are not capable of high-level cryptography and pose little threat to the bitcoin ecosystem.  Additionally, some believe that the device will also be inefficient at mining -- although I am inclined to think otherwise.  Needless to say, the challenges to the bitcoin protocol posed by QC will be met as affordable devices reach the market.  I am confident that the bitcoin community will adapt, but I do think that QC will be used to mine someday.