The astronomical margins are probably gone for the time being however...
when bitcoin was at double digits, we imagined what would happen when investors with millions usd would be coming into coins. now we know what happens, the next question is, what will happen when investors with billions usd would be coming into coins. this should happen somewhen in '14-'16 range, margins should be about the same size, different order of magnitude.
this current shitstorm does not matter, only for mid-term speculation. if anything, it shows quite a lot of maturity in the market - only 50% retraction from ATH, solid price supports ignoring the whole dying mtgox situation (remember the last two crashes mtgox was calling all the shots), stable foundation for current services development and future growth.
In addition, probably sooner than later a major bank is going to come out and publicly back and/or start getting involved in bitcoin. I guarantee they are all mitigating the risk and exposure right now, because they realize how profitable it could be for them to be the first major bank involved.