There definitely are established BTC escrow services. What I've started wondering about is also due to volatility but in the other direction: how do you prevent a loss of USD value during arbitration or otherwise incident to the transaction times? More directly, how could you enforce something that is the equivalent of an OTC futures contract to be paid out in USD? For that kind of thing, you need an escrow that deals in USD for nothing or peanuts.
- https://bitcointalksearch.org/topic/judgeme-transnational-law-or-small-claims-court-for-the-internet-83981
Also relevant to the above: in this thought experiment, the purpose would be to avoid having to pay a standard fee to either a professional arbitration judge or a professional escrow service. Shouldn't OTC counterparties be able to choose their own mutually trusted neutral party, on the OTC web of trust itself, to determine whether to release funds in escrow? It's prohibitively difficult for such a person to set up their own dollar escrow service. Your only other alternative is paying a professional service for both their infrastructure and the monkeysense they have to use in order to render judgment.
Something like StickK could act as an established infrastructure that allows neutral third parties to be enlisted to release funds in escrow in a way that requires no investment in anything other than a judgment and a few clicks. The neutral party would only need to be compensated for this brief effort, and the compensation could be anything agreed by the parties rather than being locked into an escrow service's fee structure.