I'm not sure if this will qualify for the bounty but I admire your project and thought I could put my 2 cents in. I won't bother you with random sites that offer escrow services as you now have a plethora of those, but I'll just give you my thought and trust of the whole escrow system as is.
Bitcoin, as a digital currency, deals with irrevocable transactions, because of this bitcoin has always been a viable option for scammers engaged in foul play.
Because of this systems of trust in an otherwise lawless Wild West scenario needed to be created, this is how the current escrow systems came to be.
We see these escrow systems in the current marketplace.
1-Member isolated third party escrows, where individuals act as an escrow for two other individuals.
2-Company based third part escrows, where a website will offer the service of creating an escrow that may or may not be disputable if fraud occurs.
For the most part most regular escrowing systems as seen in various lists throughout Bitcoin forums rely upon a "trusted" third party member
https://bitcointalk.org/index.php?topic=108716.0This 'trusted' status differs in how its gained from place to place but relies upon the same ideas that an individual that displays a large amount of activity upon their profile in addition to the fact that they have had a large number of successful trades is a reputable individual.
This entire scenario relies on the concept that this individual finds it more worth his time to engage in respectable transactions that allow his own trading to continue, rather than to steal and subsequently ruin his reputation thus ending his trading business.
As noticed this creates a very high risk scenario once large transactions come into play. Is the escrow willing to waste his reputation upon this sum of money?
This answer comes from looking at the only mechanisms given in the bitcoin community, his trust and activity. Sites like bitcoin-otc thrive off of these systems, but are flawed by their lack of future assurance. Nothing is stopping an individual from calling quits on bitcoin all of a sudden and running with the money.
There's a true story that's often told in the silk road forums about a dealer that was trusted throughout the black market site, to a point where his name was synonymous with silk road. He became so trusted that escrow services were no longer thought necessary within his dealings. Then one 4th of july weekend (coincidence haha) he had a firesale, where he was going to give everything away for blowout prices. The blockchain estimated that there were over 20 million dollars worth of transactions made that weekend. It is not known whether he was raided or if he died, all that was known was that the trusted dealer did not send any of his promised bud to his mates.
So despite whatever relative ease or assurance that may be given when a 'trusted' member is offering escrow, there's nothing to say that the escrow will end bad, and the more money that's escrowed, the higher the risk of total losses.
This risk was somewhat mitigated with company based escrow services that started like ClearCoin and BTcrow. These methods offered DISPUTE RESOLUTION SERVICES. ClearCoin became a leading example of the strength of this little principle but unfortunately lasted only 6 months. But in a marketplace that demands anomonitity and deals with these irrevocable transactions, escrow services like this are seeing a field ripe for picking.
As for any future implementations of new bitcoin escrow policies, the only one that I think remains relevant other than creating more trusted company based services that allow disputes and insuranced transactions is the fact that bitcoin is in fact supported by scripts. As rethaw pointed out a few posts above this allows for educated clients to create there own dispute mediation service, unfortunately this can also be subject to fraud.
